Richard Mayeux, MD, MSc - US grants

Depression, dementia, and slowing of intellectual function affect nearly half of the population over the age of 65. Investigation of degenerative diseases of the nervous system that cause these behaviors is crucial for understanding their pathogenesis and for developing rational strategies for treatment. Parkinson's disease is a common degenerative disorder of the aging nervous system that is usually conceptualized as a disorder of movement. However, it is now recognized that Parkinsonian patients develop intellectual difficulty and depressive disorders at a much greater rate than expected. Neurotransmitter alterations in Parkinson's disease include not only dopamine but also serotonin and norepinephrine. Investigation of behavioral relationships to these neurotransmitter systems could serve as a model for the study of similar problems in the aged. We intend to test two hypotheses developed from our previous investigations. First, that depression is a syndrome associated with a disorder of serotonin metabolism in Parkinson's disease, and second, that slowing of intellectual function, termed bradyphrenia, is a disorder related to a disturbance in norepinephrine metabolism. We plan to examine a large number of patients and an equal number of controls to confirm the relationships between serotonin and depression by measuring various components of serotonin metabolism, conducting a clinical trial of the serotonin precursor (5-hydroxytryptophan) in depressed Parkinsonians, and monitoring the prevalence of depressive symptoms in Parkinsonians with a reduction in the metabolite of serotonin in cerebrospinal fluid. To further examine our second hypothesis, we intend to re-explore the relationship of bradyphrenia to norepinephrine metabolism in both cerebrospinal fluid and plasma. We also intend to conduct clinical trials of two norepinephrine agonists in Parkinsonians in order to explore the role of catecholamines in intellectual function. This investigation has direct application to Parkinson's disease, but more importantly, it will broaden our understanding of the relationships between behavioral changes and biochemical alterations in diseases of the aging nervous system.

This investigation will determine the timing and the clinical and biological significance of brain atrophy and white matter lesions seen in magnetic resonance imaging (MRI) of patients with human immunodeficiency virus (HIV). This study is part of an ongoing investigation at the HIV Center for Behavioral and Clinical Studies at the New York State Psychiatric Institute which examines the natural history and evolution of neurological and neuropsychological manifestations of HIV infection in gay men and parenteral drug abusers of both sexes. The primary objective of this new investigation is to determine the relationship of abnormalities on MRI to the prevalence, progression and incidence of neuropsychological, neurological, and virological parameters of disease in cerebrospinal fluid (CSF). We hypothesize that MRI will reveal the earliest signs of central nervous system infection by HIV. Atrophy and white matter lesions will precede or occur simultaneously with neurological and neuropsychological changes and will correlate with virological evidence of infection in CSF. A representative sample of the cohort being investigated for natural history of HIV will have MRI on an annual basis and a subsample will have CSF examinations to determine the psychobiological correlated of the radiological manifestations. Over four years we intend to determine the prevalence and incidence of MRI abnormalities in gay men and parenteral drug abusers who are HIV positive, determine the psychobiological correlates of these lesions, determine the virological parameters in CSF and determine their relationship to the HIV Center at the New York State Psychiatric Institutes, we will also examine the relationship to other aspects being investigated there, such as psychopathology, sexual behavior and immune status.

This program project will investigate the epidemiology of dementia in the urban community of North Manhattan, also known as Washington Heights-Inwood. This interdisciplinary investigation will focus on the epidemiology of the three common causes of dementia in the elderly: Alzheimer's disease, Stroke and Parkinson's disease. The study is centered in a heterogeneous community containing three major ethnic groups: Hispanic, Black and White. Columbia Presbyterian medical Center is the only hospital serving this community, where 35,043 people over the age of 60 live in an area of about 10 square miles. The current investigation consists of three projects: 1. The North Manhattan Aging Project, a cross-cultural method to develop a registry in order to examine the prevalence and incidence of dementia in the community; 2. The Incidence of Dementia with Stroke, a community-based, hospital investigation of the epidemiology of dementia following stroke; 3. The Epidemiology of Dementia in idiopathic Parkinson's Disease, a community-based investigation of the prevalence, incidence rate and risk factors for dementia in idiopathic Parkinson's disease. The these projects are supported by three cores: Administration (including data management and statistics); Clinical-Diagnostic (including genetics and epidemiology); and Neuropathology. This program projects is centered around a unique, culturally diverse community. We intend to investigate the cultural differences in the rates, types and causes of dementia, and, where possible, examine cultural differences in risk factors for dementia.

Beta amyloid deposition may be one of several key early events in the pathogenesis of Alzheimer's disease (AD) which leads to neuronal degeneration, but the etiology of this process is unknown. In a few families with inherited AD, a single amino acid substitution in the amyloid precursor protein gene (APP) may lead to a subtle alteration in the metabolism of this peptide. AD might also be caused by the release of beta amyloid following head injury. Thus, the etiology of AD is likely to be the result of both genetic and environmental factors. We intend to exploit and extend this view by proposing that the cause of AD may also result from an interaction between genetic and environmental factors. Similarly, the etiology of dementia in Parkinson's disease (PD), although clinically and pathologically similar to AD, is not known. To achieve a concentrated and unique effort we shall: a) amplify existing research on AD and related dementias by incorporating analytic studies of environmental risk factors; b) develop research in genetic epidemiology to examine the interaction between environmental and genetic risk factors; c) initiate studies of the "molecular epidemiology" of AD integrating both molecular biology and epidemiology into a large scale investigation of elderly in Northern Manhattan. Two outstanding young investigators have been identified to develop parallel programs during this proposal. Karen Marder, MD, MPH, will identify and measure the relationship between environmental and genetic risk factors in the causal pathway of dementia in PD with a case- control study building on her work showing an increased risk of AD in the first-degree relatives of demented patients with PD. Benjamin Tycko, MD, PhD, will use single strand conformation polymorphism to screen for mutations in a larger portion of the APP gene than has been previously examined in controls, patients with AD, PD and Down's syndrome. Mutations in exons might imply an abnormal production of amyloid, whereas mutations in promoter regions could indicate abnormal expression. He will also explore somatic genetic events, such as post-zygotic chromosomal nondisjunction that could lead to low level mosaic trisomy 21 resulting in "genetic basis" for sporadic AD. The intent of this proposal is to lead new and developing scientists into research for AD. The intent of this proposal is to lead new and developing scientists into research for AD. The future dictates that basic and clinical scientists must collaborate in approaching AD, we describe here a series of studies in molecular epidemiology and gene-environment interaction that should achieve that goal.

Beta amyloid deposition may be one of several key early events in the pathogenesis of Alzheimer's disease (AD) which leads to neuronal degeneration, but the etiology of this process is unknown. In a few families with inherited AD, a single amino acid substitution in the amyloid precursor protein gene (APP) may lead to a subtle alteration in the metabolism of this peptide. AD might also be caused by the release of beta amyloid following head injury. Thus, the etiology of AD is likely to be the result of both genetic and environmental factors. We intend to exploit and extend this view by proposing that the cause of AD may also result from an interaction between genetic and environmental factors. Similarly, the etiology of dementia in Parkinson's disease (PD), although clinically and pathologically similar to AD, is not known. To achieve a concentrated and unique effort we shall: a) amplify existing research on AD and related dementias by incorporating analytic studies of environmental risk factors; b) develop research in genetic epidemiology to examine the interaction between environmental and genetic risk factors; c) initiate studies of the "molecular epidemiology" of AD integrating both molecular biology and epidemiology into a large scale investigation of elderly in Northern Manhattan. Two outstanding young investigators have been identified to develop parallel programs during this proposal. Karen Marder, MD, MPH, will identify and measure the relationship between environmental and genetic risk factors in the causal pathway of dementia in PD with a case- control study building on her work showing an increased risk of AD in the first-degree relatives of demented patients with PD. Benjamin Tycko, MD, PhD, will use single strand conformation polymorphism to screen for mutations in a larger portion of the APP gene than has been previously examined in controls, patients with AD, PD and Down's syndrome. Mutations in exons might imply an abnormal production of amyloid, whereas mutations in promoter regions could indicate abnormal expression. He will also explore somatic genetic events, such as post-zygotic chromosomal nondisjunction that could lead to low level mosaic trisomy 21 resulting in "genetic basis" for sporadic AD. The intent of this proposal is to lead new and developing scientists into research for AD. The intent of this proposal is to lead new and developing scientists into research for AD. The future dictates that basic and clinical scientists must collaborate in approaching AD, we describe here a series of studies in molecular epidemiology and gene-environment interaction that should achieve that goal.

Investigators have used 2 approaches to probe the cause of Parkinson's disease (PD):epidemiologic methods to identify putative risk factors; and both genetic-epidemiologic and biochemical techniques to detect genes that might confer genetic susceptibility to PD. However, there has been no definitive cause identified as yet, and there is evidence to imply that both environmental and genetic factors may be involved. In this investigation we propose to examine a number of putative antecedent environmental risk factors and their relationship to one putative marker of genetic susceptibility to PD. Using a case-control design we will compare the frequency of specific dietary, environmental and genetic risk factors in patients with PD and the controls all of whom will be 65 years of age or older and residing in the community of Washington Heights-Inwood. Recently diagnosed patients with PD without evidence of dementia and healthy elderly controls, free of PD and dementia, identified during the funding period of another project will form the subject groups for this investigation. All cases will have met rigorous research criteria for the diagnosis of PD and have been diagnosed within the last 5 years, and controls will be selected from a random sample of elderly from the same community (participating in another study) by frequency matching for age (by 2 years) ethnic group and gender. We will conduct standardized interviews to obtain a detailed dietary information and to ascertain exposure data regarding putative risk factors. Serum ferritin will be determined as a measure of body iron stores and we will also collect blood to extract DNA in order to determine the frequency of various CYP2D6 debrisoquine hydroxylase gene alleles in both cases and controls. We will examine CYP2D6 locus-environment interaction by examining the associations between the presence of CYP2D6 polymorphisms and various dietary or environmental risk factors. We intend to investigate 2 major hypotheses: First, that regular consumption of foods high in dietary iron, in elderly individuals with normal or decreased body stores of iron, will b associated with PD. Second, that a specific CYP2D6 allele will be a marker of genetic susceptibility to PD, and that exposure to putative environmental risk factors may further increase the risk of PD in these genetically susceptible individuals.

The mandate of "Healthy People 2000 is a 20% reduction in the number of people, aged 65 years and older, requiring assistance for personal care activities by the year 2000. This goal can only be fully realized by identifying he etiologies and consequences as well as the determinants of the course and incipient signs of a major cause of impaired function in the elderly: Alzheimer's disease (AD) and related dementias, particularly stroke. During the previous funding period, we developed a population-based registry for dementia and used information from this resource to investigate the epidemiology of AD and other forms of dementia (stroke and Parkinson's disease) in the ethnically diverse community of Washington Heights-Inwood in New York City. We have completed estimates of the prevalence and incidence of dementia, primarily AD and the dementias associated with stroke and Parkinson's disease (PD). We used the case-reporting system or registry: 1) to develop methods to assess dementia that consider the various cultural and educational backgrounds of our community; 2) to identify clinical predictors for various types (SRD) and PD in a series of case-control studies using recently diagnosed cases and controls from this community. In this renewal application it will become apparent that we have strengthened and streamlined our methods for case-ascertainment and follow up by merging the diagnostic screen and neuropsychological assessment into a single step at the same interview using computer technology. We have incorporated functional assessment by field and laboratory methods and biologic markers (brain imaging and bioassays) into this renewal. We intend to investigate specific hypotheses developed through the relationship of the North Manhattan Aging Project and the Clinical Core in the previous funding period. First: environmental, dietary and genetic factors associated with incident AD, stroke and SRD will be explored; in second functional and biological correlates and consequences of cognitive decline and its relationship to incipient dementia will be investigated; and third: the late consequences and course of AD will be explored. Finally, using our community base we shall confront issues we consider fundamental to the etiology, course and late consequences of AD and related disorders.

The primary aim of this project is to assess and evaluate Alzheimer's Disease (AD) and related neurodegenerative disorders in an elderly population. Subjects are drawn from a regionally and ethnically diverse population, with a specific emphasis on those residing in northern Manhattan. The Core will (1) emphasize the development of reporting and screening techniques which are culture-fair and culture-free; (2) perform clinical evaluations, including memory testing and review of history and lab studies, with social services available as needed; and (3) study prevalence, incidence, prognostic features and outcomes of dementia. Longitudinal follow-up will be encouraged on the average of every 6-12 months. The Clinical Core serves as a referral source for therapeutic trials within the Alzheimer's Disease Cooperative Studies Unit.

DESCRIPTION: The aetiology of idiopathic PD (IPD) is complex, involving genetic and environmental factors. The risk of IPD is higher among relatives of cases than controls, but only a small number of multigenerational families with IPD exist. In support of an environmental cause, are the observations that MPTP and occupational manganese exposures both induce PD. Iron accumulates in the substantia nigra in IPD and lactoferrin receptors are increased whereas ferritin concentrations are reduced. This imbalance of iron is posited to accelerate free radical formation and lipid peroxidation. In IPD, activity in complex I of the respiratory chain is reduced in the substantia nigra, particularly for subunits encoded in the mitochondrial genome. MPTP inhibits NADH-CoQ reductase (complex I) in mitochondria, whereas manganese inhibits the Citric Acid Cycle enzyme, mitochondrial aconitase (ACO2). Deficits in ATP production in certain critical neuronal populations are posited to indirectly contribute to the pathogenesis of IPD. During the first three years, the applicants found that, in comparison to controls, patients with IPD have lower concentrations of iron storage and transport proteins, indicating a perturbation in systemic iron metabolism. The patients also have increased caloric intake, suggesting a defect in energy metabolism. The applicants have detected a shifted protein band in serum which, by Western blot, contains ACO2. They also found evidence for allelic association of two dinucleotide repeat makers on chromosome 22q13, which includes the ACO2 gene. These observations lead to the hypothesis that IPD may be the result of a mutation, splicing variant or post-translational modification of ACO2 which, in turn, alters mitochondrial function. The current plan is to extend the epidemiologic inquiry by investigating changes in iron metabolism and caloric intake in IPD, over time and at two critical diseases stages, early (untreated) and late. Additionally, a major laboratory effort will be employed, not only to characterize and determine the frequency of altered forms of ACO2 in IPD and controls, but also to identify ACO2 mutations or splice variants if they exist, and to investigate mitochondrial function in relation to altered ACO2.

Research efforts in the Neurotoxicology/Neurodegenerative Disease Research Core will be under the direction of Dr. Richard Mayeux and will span clinical, epidemiological, and mechanistic studies of lead and mercury poisoning and neurodegenerative diseases including Parkinson s and Alzheimer?s disease. It is anticipated that Dr. Mayeux will form task-oriented working groups which will focus on specific problems within areas of interest. Members of the faculty, postdoctoral fellows and doctoral students will meet monthly to discuss topics of ongoing interest in one of the following areas: 1) gene-environment interactions in the neurodegenerative diseases of aging; 2) molecular mechanisms involved in the perturbation of iron metabolism as it relates to Parkinsonism; 3) genetic susceptibility to Parkinson s disease in first-degree relatives of both sporadic and familial cases and the pattern of inheritance; 4) the genetic bases of essential tremor and Alzheimer?s disease; 5) effects of lead on cognitive performance and development of children; 6) relationships between occupational exposure to mercury vapor and the risk of tremor, peripheral neuropathy, cerebellar dysfunction and measures of abnormal balance; 7) mercury exposure derived from amalgams in the mouth and possible associations with neurological dysfunction or neuropsychological deficits; 8) caloric intake, body mass index and the risk of neurodegenerative disease; 9) mitochondrial function in normal aging, Parkinson s and Alzheimer s disease; 10) occupational mercury exposure and the risk of memory and visuospatial ability and disturbed mood; 11) molecular mechanisms of lead neurotoxicity; 12) mechanisms of manganese-induced Parkinsonism; and 13) molecular mechanisms of MPTP. Task-oriented working groups will be composed of selected members of the research core, facilities cores and Center staff as needed. The framework in which these work groups will operate will be flexible and will address specific research concentrations dictated by the overall focus of the Center. The specific aims are as follows: 1) to stimulate and guide interdisciplnary research on neurodegenerative diseases; 2) to stimulate and guide research on neurotoxicology with an emphasis on the neurotoxicity of transition and heavy metals; 3) to expand mechanistic and epidemiologic studies among the elderly of Northern Manhattan and; 4) to extend research efforts concerning the interaction of genetic susceptibility markers and environmental exposures in Parkinson?s and Alzheimer?s Disease. It is anticipated that highlights of meetings held in the 12 research areas will be presented at the bi-weekly work-in-progress meetings and that these meetings will provide a vehicle for communication of progress to other members of the Center and outreach programs.

During the previous funding period we made several key observations in a follow-up study of a healthy elderly cohort. 1) The prevalence and incidence of Alzheimer's disease (AD) and dementia associated with stroke (DAS, defined broadly as dementia in individuals with evidence of cerebrovascular disease) were significantly higher among African-Americans and Hispanics than Caucasians. 2) The cumulative incidence of AD to age 90 was significantly higher without, than with, and APOE-epsilon4 allele among African-Americans and Hispanics compared to Caucasians. 3) AD risk was significantly lower among postmenopausal women who used estrogen compared to women who did not, regardless of their age, APOE genotype, education or ethnic background. 4) The risk of DAS is higher among individuals with an APOE-epsilon4 allele and preliminary evidence suggests that increased levels of low density lipoprotein (LDL) and an increased ratio of total cholesterol to high density lipoprotein (HDL)-cholesterol imposes a higher risk of DAS. These observations and others described in preliminary work provide a unique opportunity to understand mechanisms related to the disease risk and risk reduction. We shall expand our epidemiologic inquiry in this multi-ethnic community by refreshing the follow-up cohort and enhancing the laboratory component. We will study the cumulative risk of AD across ethnic groups by analysis of APOE flanking region haplotypes to identify polymorphisms in enhancer/promoter regions of APOE. We will study the cumulative risk of DAS in relation to lipids and lipoproteins and APOE genotype and investigate the stroke subtype sin DAS. We will study the cumulative risk of AD by amyloid beta proteins 1-42 and 1-20 in plasma and investigate changing levels of these proteins with disease progression. We will study the cumulative risk of AD and DAS by systemic levels of gonadal and adrenal steroids and continue our investigation of protective factors such as non-steroidal anti-inflammatory drugs, alcohol and increased physical activity as well as other risk factors such as smoking. The new cohort will allow us to exploit the findings in our previous funding period and develop a significantly enhanced laboratory investigation of genes and biological indicators of risk and risk and risk modification of AD and DAS.

Hispanics, particularly those from the Caribbean Islands, currently represent 4 percent to 6 percent of population over age 65, but they are the most rapidly increasing ethnic group in this age category in the US. With the increase in numbers of Hispanic elderly, this ethnic group will face many of the diseases associated with advanced age, such as Alzheimer's disease (AD). We find evidence of a higher prevalence of AD among Hispanics in New York City, and the risk of developing AD in this population also appears to be increased. Mutations that result in an early onset, autosomal dominant form of AD have never been investigated in this growing population in the US. While we have found the epsilon4 polymorphism of APOE on chromosome 19 to only slightly increase risk of AD in Hispanics, we have also observed a 3-fold higher risk of AD among Caribbean Hispanics compared to Caucasians with the APOE-epsilon3/epsilon3 genotype. This implies the existence of other genes or environmental factors that increase AD risk. Appropriately designed, population-based investigations of environmental factors associated with AD are already in progress by our group. To identify genes that increase the risk of AD, families or sibling pairs are more appropriately studied. In this revised application, we hypothesize that one or more AD susceptibility genes, other than APOE, exist in Caribbean Hispanics. We will focus on the genetic influences on AD risk among patients and their siblings in the Caribbean Hispanic population in New York City and the Dominican Republic. Specifically, we propose to chromosomally localize genes that increase risk of AD by collecting detailed clinical information on 450 sib-pairs with AD in New York City and the Dominican Republic, continue to search for large, extended pedigrees with late-(or early-) onset AD, establish transformed cell lines in AD sib-pairs and families, conduct genetic linkage analyzes in the affected sib-pairs and extended pedigrees using semi-automated fluoresecently-labeled microsatellite genotyping and explore the genetic relationship of APOE to any mapped susceptibility locus. The ultimate goal of this project is to chromosomally localize genes that may increase the risk of AD among the Caribbean Hispanic ethnic group.

We previously reported the age-specific incidence rate for idiopathic Parkinson's disease (IPD) among women and Black Americans to be equal, and in some instances higher, than that among men and Whites. In contrast, the age-specific prevalence was significantly lower for women than men and lower for Blacks than Whites, consistent with the prevailing observations. The lower prevalence in this community study was, in part, explained by the observation that mortality for Blacks with IPD was 3 times that for Whites, but this did not explain the lower prevalence among women compared with men. Using a combination of data resources available to us, we will address a series of hypotheses related to gender and ethnic differences in the prevalence, morbidity and mortality associated with IPD. This investigation capitalizes on the four ferally supported projects in place providing data on nearly 900 patients with IPD and similar data on 1800 individuals from the same geographic region without IPD. First, we will investigate ethnic and gender differences in disability and death, expand data gathering on co-existing health conditions, institute an annual follow-up program to capture several physical and cognitive measures that are currently measured at baseline and obtain death certificates for all decedents. We will use a disease risk classification scheme for all co-morbid and associated conditions including dementia, atherosclerotic disease and stroke. Using the additional follow-up data specifically collected for this project, ethnic and gender differences in total life expectancy (TLE) and active life expectancy (ALE) will be compared for those with and without IPD and among those with IPD to calculate years of life or active life lost due to the illness. Secondly, we will use our data and existing secondary databases containing clinical, survey, and death certificate information to complete a validity analysis between administrative and clinical data sources, characterizing and quantifying factors and bias associated with ethnic differences in the recording of Parkinson's disease on death certificates. The clinical relevance of the latter is related to the belief that Blacks and women are at significantly lower risk from Parkinson's disease-a concept, whose strongest support lies in numerous large studies of death certificate.

DESCRIPTION: (Abstract from application) For this exploratory proposal, we will develop the hypothesis that active survival into old age is highly dependent on the preservation of cognitive and physical function, and that the preservation of these functions is, in part, inherited. We will use longitudinal data from two cohorts of elderly African-Americans, Caribbean Hispanics and whites in northern Manhattan and their families to identify potential candidate phenotype definitions for genetic analysis. The phenotypes of interest will be related to the rate-of-change with age in cognitive and physical function, and to the age at which individuals reach critical stages in these functional domains. First, previously collected longitudinal data will be used to determine the rate-of-change with age in specific measures of cognitive performance and physical function, develop specific indicators of clinically meaningful changes corresponding to the loss of ability and determine the age-at-onset of these changes within strata defined by ethnic group, major disease categories, lifestyle factors and specific allelic polymorphisms. Interactions between genotypes and disease and lifestyle factors will be explored for their combined effects on the rate-of-change and the age-at-onset of specified changes in cognitive or physical function. Shared genetic effects on the phenotypic measures and years of total and active survival will be investigated in these individuals and their first-degree family members. In a recently established cohort we will recruit their same-sex siblings to analyze concordance in cognitive and physical function, concordance in rate-of-change in these functions based on retrospective interviews and familial aggregation of time-to-event measures in probands and first-degree relatives. We will collect and store DNA from examined siblings for future linkage or association studies, and we will assess the feasibility of repeated examinations in the siblings, in terms of participation and attrition rates, loss to follow-up, location of examinations, clinical procedures to be included, etc. We will use the experience in this multi-ethnic community to obtain information about phenotype definitions, study designs, sample size requirements, and analytic tools to detecting genes influencing the rate-of-change in cognitive and physical function.

DESCRIPTION: (provided by applicant) During the funding period we identified, examined and collected blood samples from 1150 individuals from 301 families of Caribbean Hispanic origin with familial Alzheimer disease, and are currently processing data already collected in another 77 families (281 individuals). We have completed a first-stage genome-wide scan consisting of 340 markers in the first 98 families identified, and we have successfully applied to Center for Medical Genetics at the Marshfield Medical Research Foundation to have the remaining families genotyped. In our first-stage genome scan, we observed several peaks with parametric two-point lod scores exceeding 1.0, but the highest lod scores were 3.15 at chromosome 18q21 and 2.00 at chromosome 12p 12. Using non-parametric multipoint analyses we identified several NPL scores with p equal to or < 0.05, but the highest NPL scores were on chromosome 18q21 (p=0.003) and 10q26 (p=0.007). We will present encouraging new data from the initial fine mapping in these regions in the progress report. During the next 5 years, we will perform studies to fine map these chromosomal regions and to identify the corresponding genes. Our hypothesis remains that one or more susceptibility genes, in addition to APOE, increase the risk of Alzheimer's disease among Caribbean Hispanics. The overall goal of this project is to identify variations in genes among Caribbean Hispanics that increase the risk of developing Alzheimer's disease. First, we propose to expand fine mapping in the Knowles and Tycko laboratories at Columbia University and the St George-Hyslop laboratory at the University of Toronto of genomic regions with strongest support for linkage on chromosomes 18, 10, 12 and 21 from our initial genome scan. Second, we will conduct genetic linkage analyses using the new marker data provided to us by The Center for Medical Genetics at the Marshfield Medical Research Foundation using the entire set of families. By contrasting and comparing the results of the 1st and 2nd scans we will improve map resolution and prioritize subsequent fine mapping efforts. We will follow-up the entire cohort of existing families to confirm diagnoses, assess disease progression, discuss autopsy permission, re-examine those at risk and extend phenotypes. We will collect clinical information and obtain blood to establish cell lines in an additional 300 Caribbean Hispanic families with Alzheimer's disease to augment fine mapping. We will confirm any putative candidate gene from the fine mapping efforts in the independent Caribbean Hispanic population sample in New York City. Further we will make cells lines and clinical information available to others through the National Cell Repository for Alzheimer's disease.

genetic susceptibility; gene environment interaction; disease /disorder proneness /risk; nervous system disorder epidemiology; Alzheimer's disease; racial /ethnic difference; Hispanic Americans; memory; dementia; gene mutation; African American; caucasian American; clinical research; interview; blood tests; human subject;

DESCRIPTION (provided by applicant): The biological mechanisms and environmental influences mediating exceptional survival (ES) into old age remain unknown, but genetic factors are likely to play an important role. ES is a complex phenotype characterized by exceptional longevity and by the lack of significant morbidity or disability. In preliminary work, we found that siblings of elderly probands with little decline in memory, cognitive function and activities of daily living skills were one-half as likely to die as siblings of probands with more rapid decline in these areas of performance. These findings suggest that long-lived families are characterized by preservation of cognitive and functional capacities and good health status. However, a wider exploration of other traits associated with ES is needed to identify groups of families with specific patterns of survival associated with ES to improve our ability to detect genetic loci. While it is critical to fully define and investigate the phenotype of ES, to detect contributing genes with large or small effects it is equally important to examine intermediate phenotypes that are manifestations of the phenotype of ES. Such studies rely on large numbers of well characterized families.The goal of this proposal is two-fold. First, we will determine the patterns of occurrence and modes of transmission of ES by a family history study of approximately 600 elderly residents, aged 95 years or older, residing in the New York, New Jersey, and Connecticut tri-state area. Participants will be identified and recruited from a population based sampling frame of 29,000 elderly individuals provided to us through the Center for Medicare and Medicaid Services. Second, we will identify and recruit approximately 300 families with exceptional survival in multiple family members from the family history study. We will conduct a family study of phenotypes that best characterize ES, including phenotypes for cognitive, physical, functional, disease status and physiologic capacities to determine heritable traits that subserve the overall phenotype of ES. We will also obtain information concerning environmental, social and behavioral factors that may contribute to ES. These families will be asked to provide blood to establish lymphoblastoid cell lines for subsequent genetic linkage studies. This team of investigators has worked together for the last 10 years and comprises researchers from epidemiology, genetics, neurology, neuropsychology and biostatistics. The investigative team has extensive experience in the use of CMS data to identify and recruit large cohorts for epidemiologic and genetic studies. The results of the proposed project will provide information on patterns of transmission of ES phenotypes for future genetic analyses. Identifying genes associated with ES will be an important step in understanding the processes underlying successful aging.

In this project we will critically examine two biomarkers found to be strongly associated with AD in the previous funding cycle. First, using biological samples and clinical data from the baseline assessment and first follow-up, we will greatly expand our work on plasma Abeta42 and Abeta40 by attempting to replicate our previous findings in a much larger and more extensive longitudinal study focusing on the outcomes: AD and MCI. We will have to opportunity to investigate how and when Abeta42 and Abeta40 plasma levels changes during the transition from healthy (without dementia) to MCI and then to AD, and to investigate variation in plasma levels by age, ethnic group, APOE genotype, use of antiinflammatory drugs and in relation to other putative clinical risk factors. We will investigate the relation between Abeta42 and Abeta40 in plasma and autoantibody production to AlL Second, we will broaden our preliminary work on a second biomarker: structural and functional MRI. Initially, we will compare the basal metabolism in the entorhinal cortex, dentate and CAt subregions of the hippocampus and the volume of the hippocampus in healthy elderly and those with individuals who have MCI using a cross-sectional approach. We will then examine the association between APOE-epsilon4 and variation in the TP73 gene in relation to the size and basal metabolism within the hippocampus and its subregions. We will also use the acquired imaging data to examine their association between clinical risk factors for AD. Most importantly, we will use the imaging data acquired at the second follow-up to examine the subsequent risk of MCI and AD and in relation to the basal metabolism within the hippocampus and its subregions and hippocampal volume using a longitudinal approach. Further, we will examine the change in memory and other cognitive function over time in relation to the basal metabolism within the hippocampus and hippocampal volume. The underlying premise of this investigation is that as elderly individuals progress from normal cognitive function through MCI to AD, there is a parallel sequence occurring in the hippocampus. A decrease in basal metabolism precedes the shift from normal cognitive function to MCI followed by hippocampal atrophy, which precedes the transition from MCI to AD. It is our intent to characterize the relation between these antecedent biomarkers and both clinical and genetic risk factors for MCI and AD. With our first follow-up completed and our second, third and fourth anticipated we feel we are in an excellent position to broaden this prospective investigation of elderly African-Americans, Hispanics and Caucasians, which provides a unique opportunity to understand mechanisms related to the disease risk.

Alzheimer's disease; biomedical facility; aging; longitudinal human study; medical outreach /case finding; patient oriented research; clinical research; human subject; interview; neuropsychological tests;

The Genetics Coordinating Core (GCC) at Columbia has been in existence for two years. The Core was initially supported through a supplement from the National Institute on Aging (NIA), Alzheimer's Disease Research Centers (ADRC/ADC) Program, with the goal of coordinating the collection of families in which two or more individuals have Alzheimer's disease from the collaborating centers. The overall program is entitled the NIA-Genetics Initiative for Late-Onset Alzheimer's Disease (NIA-LOAD Study). The collection of these families was designed using a multi-center approach that originally included 10 ADCs and was later expanded to include 18 centers for which Columbia University's ADRC has been the Coordinating Center. In addition, ADCs not included in the NIA Genetics Initiative have been able to submit families for consideration. Over the past year and a half, the GCC at the Columbia ADRC has developed, circulated and refined a procedures manual, reviewed and approved over 500 families for inclusion in the National Cell Repository for Alzheimer's Disease (NCRAD), specified the type of data to be collected and transmitted to NCRAD and have developed standardized format to collect age-at-onset, assess cognitive performance, collect biomarkers and autopsy material. The goals for the GCC over the next 5 years are to: expand the current collection of families by identifying and examining new families meeting NIA-LOAD criteria for inclusion, assist the participating centers to identify newly affected family members within existing families, develop and implement follow-up procedures, including autopsy, for the participating families and family members, facilitate and coordinate the recruitment of up to 1,000 individuals unrelated to the participating families without dementia to form "control" group similar in age, sex and ethnic background for association analyses by using similar methods to identify potential individuals, and develop and implement methods for standardized assessment of a series of quantitative traits for application in the NIA-LOAD study.

[unreadable] DESCRIPTION (provided by applicant): Over the past two years the NIA-Late-Onset Alzheimer's Disease (NIA-LOAD) Study was developed for the recruitment of individuals from families with late onset familial Alzheimer's disease and supported through supplements to 18 Alzheimer's Disease Centers. This group, led by a Genetics Coordinating Core (GCC) at Columbia University has developed, circulated and refined a procedures manual and has overseen the collection of 1,885 samples from 422 families for which data has been transmitted to the National Cell Repository for Alzheimer's Disease (NCRAD) located at Indiana University. The intent of this Resource-Related Research Project-Cooperative Agreement is to complete the collection of new families, recruit appropriate members in existing families and initiate and complete follow-up in all participating families. Five of the original Centers (Columbia University, Indiana University, Mayo Clinic, University of Washington and Washington University) will form a consortium with the existing GCC at Columbia University and will also coordinate follow-up of existing families through small targeted subcontracts with the remaining 13 Centers. The aims of this proposal are to: l)Complete the current collection of 1,000 families; 2) Identify newly affected family members and appropriate unaffected members by expanding pedigrees in participating families; 3) Develop and implement standardized follow-up procedures for the participating families and family members; 4) Improve statistical power of the sample for genetic linkage analysis by implementing methods for standardized assessment of a series of quantitative traits at the time of follow-up for all families; 5) Complete the recruitment and begin follow-up of 1,000 individuals unrelated to the participating families without dementia to form a "control" group; 6) Apply to the Center for Inherited Disease Research to have genotyping completed in the first 500 families. At the conclusion of this five year proposal we will have created a rich resource of 1,000 well-characterized families with late-onset, familial Alzheimer's disease, which is essential for the success of genetics research in this area. The NIA-LOAD Study has added specific criteria for the inclusion of families with late-onset disease and has used standardized methods to identify affected and unaffected individuals across Centers. This collection of families will be complimented by a similar number of unrelated controls. The need for additional, well characterized families is essential for identifying the remaining genetic variants and role in the disease. This application proposes to work with the network of NIA supported Alzheimer's Disease Centers to provide the resources critical to Alzheimer's disease researchers that will allow the elucidation of susceptibility genes. [unreadable] [unreadable] [unreadable] BACKGROUND, SIGNIFICANCE, AND INNOVATION [unreadable] [unreadable]

DESCRIPTION (provided by applicant): Our project is an epigenomic approach to understand the pathogenesis of Alzheimer's disease (AD), a degenerative disorder of neurons that is the most common cause of age-related dementia. Much prior emphasis in AD research has been on genetic studies, which have uncovered the fundamental involvement of the APP, APOE and PS1 genes. But with the exception of polymorphisms in APOE, known coding variants in these genes are quite rare, and the existing data do not fully account for the heritability of AD in the general population. Additional chromosomal loci that influence AD susceptibility have been uncovered by genome scanning, but while several of these loci have been confirmed in multiple studies, the causative or predisposing genetic variants have not been clearly pinpointed. New approaches are needed to get through this roadblock, and we believe that the novel combined epigenetic-genetic strategy that we propose here can be transformative in solving this problem. The equally important question of why AD is inexorably progressive, at least in our current ignorance of effective treatments, also has no clear answer. It is safe to say that progression to neuronal cell death occurs after a threshold of cellular damage, but what the crucial damage is and how it accumulates over time are largely unknown. A component of this damage may be epigenetic, including altered DNA methylation. In this collaborative and multi-disciplinary project we will bring genome-wide epigenomic profiling methods to bear on 2 working hypotheses. First, we postulate that epigenetic aberrations in the brain are involved in the progression of AD, and that genome-wide analysis of DNA methylation in cerebral cortex from early to mid-stage AD cases, compared to control brains, will pinpoint biologically relevant loci that are recurrently affected by gains or losses of net DNA methylation (affecting both alleles) in this disease. Second, our genome-wide epigenetic analysis will pay off, at no additional cost, in the identification of loci with sequence-dependent allele-specific DNA methylation (ASM) and allele- specific gene expression (ASE), thus pinpointing regulatory polymorphisms that act to establish inborn and stable inter-individual differences in gene expression in brain cells, in part through haplotype- dependent epigenetic modifications. We expect that among these sequence variants will be some that affect inter-individual differences in susceptibility to AD. The list of candidate loci from our epigenomic profiling will be brought forward for narrowly focused and thus cost efficient genetic fine mapping in the valuable well characterized cohorts of AD case and controls that are available through the long- standing collaborative relationship of the 2 PI's.

The ADRC Genetics Core (ADRC-GC) will provide a centralized resource for the organization and analysis of DNA and genetic data for the entire center, for project 3 in this funding cycle and for projects affiliated with the ADRC requiring the human genefic resources (e.g. NIA-LOAD Family study). Our overall goals are to facilitate the understanding of the associations between Alzheimer's disease or related neurodegenerative dementias and genetic variants, and to provide relevant information to investigators and patients and families. The ADRC-GC will be composed of four components already well integrated into the Columbia ADRC. 1) A DNA repository which includes data management to track biological sample inventories in coordinafion with the main ADRC database management core; 2) A stafisfical genefics and genefic epidemiology group to facilitate research involving genefic variables; 3) A genomics facility with Affymetrix, lllumina and Sequenom platforms that can handle various sized projects; 4) Two board certified genefic counselors with expertise in neurodegenerative disorders available to help clinicians and families. The ADRC-GC will coordinate the research efforts of each of these sections, such that the resources from each section are optimally used to best address scientific questions..

DESCRIPTION (provided by applicant): We will exploit the multicenter Long Life Family Study (LLFS), a unique resource for research on human longevity and healthy aging, to find genetic variants associated with these traits. In the current period, we successfully enrolled and extensively phenotyped 4,953 individuals in 539 two-generational families that demonstrate clustering for exceptional survival in the upper generation. Fewer than 1% of the Framingham Heart Study (FHS) families (a roughly random sample of families) would meet the minimal entrance criteria for exceptional survival required in the LLFS. Thus our least exceptional families show more clustering for exceptional longevity than 99% of the Framingham families. Further, the children's generation have significantly lower rates of major diseases of aging including diabetes, chronic pulmonary disease, peripheral artery disease and show significantly more favorable profiles of quantitative mariners of healthy aging such as blood pressure, lipids, functional performance, and cognitive indices compared to FHS. These endophenotypes show greater clustering (with high heritability) in the LLFS familiesthan in FHS. Thus, LLFS has likely greatly enriched the prevalence of any gene variants for longevity and healthy aging endophenotypes, thereby increasing detection power. Most importantly, the family design of LLFS provides additional power and analytic opportunities to discover genetic influences than would be possible in a study of unrelated individuals, especially with regard to rare alleles. Our specific aims are to: 1) continue phenotyping by assaying biomarkers of healthy aging on stored samples, annually tracking subjects for new significant medical and health events, and comparing Medicare (and Danish equivalent) disease and utilization data with reference samples;2) identiy common genetic variants for healthy aging and excepional survival using GWAS;3) identify rare variants for exceptional survival and healthy aging by targeted sequencing;and 4) more clearly dissect the genetic architecture of exceptional survival an healthy aging through a systems approach involving genet networks and pathways, to better understand the complex interplay between genetic variants, exposures, and covariates in the development of endophenotypes. Taking a multidisciplinary approach involving clinicians, demographers, geneticists, epidemiologists, and computational scientists, we propose to capitalize on the investments already made in creating this unique cohort to further our understanding of the nature of exceptional survival and healthy aging. PUBLIC HEALTH RELEVANCE: Exceptional longevity and healthy aging are highly enriched in the families enrolled in the LLFS thus allowing us a unique opportunity to discover both common and rare genetic associations with these traits. Such associations will not only markedly enhance our understanding of why some people age so much better than others, but will also lead to enhanced prognostication for healthy and unhealthy aging and potentially disease prevention strategies.

DESCRIPTION (provided by applicant): The overall theme of this new project is to establish and validate blood- and imaging-based biomarkers associated with the risk and progression of late onset Alzheimer's disease (LOAD), mild cognitive impairment (MCI) and the rate of cognitive decline in late life. We also propose to develop a framework with which we can understand how biomarkers interact and how they fit into the temporal sequence from healthy aging to dementia. This proposal is built on two decades of epidemiological research and systematic data collection in the multi-ethnic, Washington Heights, Hamilton Heights, Inwood, Columbia Aging Project (PO1AG07232). Over the past 20 years, we have investigated the rates of LOAD, MCI and cognitive decline in this urban community in northern Manhattan. We have investigated environmental, health-related and genetic risk factors of disease and predictors of disease progression by collecting longitudinal data on cognitive performance, emotional health, independence in daily activities, blood pressure, anthropometric measures, cardiovascular status and selected biomarkers in this elderly, multi-ethnic cohort, including lipids, amyloid peptides, sex hormones, homocysteine, insulin and C-reactive protein (CRP), and MRI. We have reported that the rates of disease and the frequency of disease risk factors vary across ethnic groups. We have identified one of the largest, multi-ethnic groups of incident LOAD cases facilitating studies of disease progression. Clinical and genetic data as well as biological resources are present for several thousand individuals. Biomarkers, cellular, biochemical or molecular alterations measurable in human tissues, cells, or fluids or by radiological means, are typically chosen because they are directly or indirectly in the causal pathway of disease. The emergence of structural and functional brain imaging has revolutionized epidemiological studies, particularly those using biomarkers for Alzheimer's disease. Positron emission tomography brain imaging using 11C Pittsburgh compound B is considered an in vivo measure of brain amyloid plaque load, while structural MRI, especially changes in brain volume and cerebral blood flow (CBF), can be considered an in vivo measures of neurodegeneration. In this new proposal, we will focus this longitudinal investigation on two sets of blood biomarkers that not only show consistent and robust associations to the risk of LOAD, MCI and cognitive decline, but that address the putative mechanisms related to amyloid burden and insulin resistance. We will take full advantage of the prospective design in this multi-ethnic cohort and the clinical, biological and brain imaging data collected to address six major hypotheses. The first two primary specific aims consider blood biomarkers as not only predictors of cognitive decline, MCI, LOAD and LOAD progression, but also as intermediate steps in the disease pathway, including neurodegeneration and cerebrovascular burden (MRI) and amyloid plaque load (PIB). In the last primary specific aim, brain imaging variables are predictors and cognitive decline, MCI, LOAD as well as LOAD progression are main outcomes. PUBLIC HEALTH RELEVANCE: There is general agreement that developing biomarkers that measure the risk of cognitive decline, LOAD and related diseases as well as the rate of disease progression would greatly enhance clinical, epidemiological, and pharmacological research. Furthermore developing biomarkers that can be easily obtained using standard and acceptable medical procedures such as blood samples or brain imaging would facilitate their use in developing methods to delay or prevent disease in the general community. Therefore the potential public health impact of developing reliable and valid biomarkers in a multi-ethnic community is a major benefit of this proposed investigation.

DESCRIPTION (provided by applicant): Much prior emphasis in research on Alzheimer's disease (AD) has been on genetic studies, which have uncovered the fundamental involvement of the APP, APOE and PS1 genes. But with the exception of polymorphisms in APOE, known coding variants in these genes are quite rare, and the existing data do not fully account for the heritability of late-onset AD (LOAD) in the general population. Additional chromosomal loci putatively influencing AD susceptibility have been uncovered by genome-wide association studies (GWAS) and related high-throughput genomic scans, but replication has been uneven and the causative or predisposing genes have not been clearly pinpointed. Further it has not been possible to gauge the importance of numerous sub-threshold statistical peaks in these scans. New approaches are needed to get through these roadblocks, and we believe that a combined strategy to first obtain lists of loci with sequence-dependent allele-specific methylation (ASM) and/or allele-specific mRNA expression (ASE) in human cerebral cortex, and then overlap this information with statistical peaks from GWAS, will help to solve this problem. We will screen for ASM/ASE in human cerebral cortex using microarray-based and sequencing-based methods. We will validate the strongest candidate loci for ASM/ASE using independent assays, and overlap the list of such loci with data from existing and ongoing GWAS in LOAD. Loci from the intersection of these 2 datasets will be subjected to highly focused and thus cost efficient genetic fine mapping in 3 independent well characterized cohorts of LOAD case and controls. Our reasoning is that sequence-dependent ASM/ASE in or near specific genes in the cerebral cortex will be a robust indicator for the presence of bona fide cis-acting regulatory polymorphisms (rSNPs, rCNPs) that confer inter-individual differences in the expression of specific genes in the human cerebral cortex, and that within this set of genes will be some that cause inter-individual differences in LOAD susceptibility. Reproducible signals from GWAS and related genome scans for LOAD that overlap with loci that show ASM and/or ASE will thus have a strong functional underpinning and warrant further intensive study as biological contributors and potential therapeutic targets in LOAD.

DESCRIPTION (provided by applicant): A current theme underlying research for genetic influences in complex diseases such as late onset Alzheimer's disease (LOAD) is the common disease, common variant hypotheses. This theory posits that multiple common variants underlie the cause of LOAD. The goals of this project is to validate and quantify the clinical impact of these newly identified genetic risk factors, namely SNPs in PICALM, CLU, BIN1, MS4A gene clusters, CD33, CD2AP, ABCA7 and EPHA1 using the multiplex families recruited through the National Institute on Aging-Late Onset Alzheimer's Disease Family Study (NIA-LOAD). The availability of rich phenotypic and molecular genetic information in these families places us in a unique position to estimate the genotype relative risks for these variants and others identified in the recent GWA meta-analyses and the exome sequencing projects currently underway. The proposed longitudinal follow-up, the characterization of additional relatives with ascertainment of antecedent risk factors, and recruitment for autopsy will also greatly benefit the field by expanding the scientific value of the NIA-LOAD Family Study. This resource of families provides distinct advantages for characterizing the impact of genetic variants on disease risk. First, multiplex families are likely to be enriched for genetic variants associated with increased risk, providing increased statistical power to estimate the effects. Second, analysis of these families provides insight into the remaining unknown genetic influences (i.e., the residual heritability) as well as antecedent modifying factors that interact with identified genetic variant to influence disease risk. Third, family members at risk are followed at regular intervals, facilitating prospective investigation of the effects of the genetic variants on age-at-onset as wel as the modifying effects of antecedent risk and protective factors. Finally, family data can provide information regarding the influence of known variants on the rate of disease progression and the residual heritability of disease progression. We will address two overall hypotheses: 1) the risk of late onset Alzheimer's disease differs among families and is related to the inheritance of specific genetic variants. The impact of these variants on disease risk is greater in multiplex families than in sporadic cases. Phenocopies and incomplete penetrance in families are related to modifying risk factors. 2) The rate of disease progression is genetically influenced, and related to the same genetic variants that influence disease susceptibility. PUBLIC HEALTH RELEVANCE: Although the identification of genetic associated with risk of late onset Alzheimer's disease is extremely exciting and vitally important, the clinical impact remains unknown. Families containing multiple affected individuals provides an opportunity to improve understanding of this clinical impact and estimating of the effects of carrying one or more specific genetic variants. Estimation of the risk (or penetrance of genetic variants) for LOAD associated with specific genotypes is critical for determining the clinical validity of geneti testing and screening for these SNPs. Clarifying the ways in which risk or protective factors modify the effects of the variants on disease risk could also point to the development of public health recommendations targeted to specific subgroups.

DESCRIPTION (provided by applicant): The Department of Neurology at Columbia University Medical Center serves as a rich site for multidisciplinary neurological research, with particular focus on disorders associated with the aging nervous system. In this proposal, the Brief Research in Aging and Interdisciplinary Neurosciences (BRAIN) program, we have developed a comprehensive approach to develop a formal research program for predoctoral students early in developing careers in biomedical, behavioral and clinical research. The work will be collaboratively approached through brief but intensive mentored summer research training experiences for these students, with the potential for subsequent development of a longitudinal research program. The research training will provide opportunities in basic, behavioral and clinical research through ongoing research in the fields of basic neuroscience, neuropathology, neurogenetics, neuropsychology, stroke, Alzheimer disease and related disorders, motor neuron disease, Parkinson disease and related disorders, and epilepsy, as well as neurologic clinical trials treating patients with these disorders. In addition, a comprehensive structured research education curriculum will be given over the course of the intense research experience, with topics including good clinical practice, basic research methodologies, introductions to abstract authorship and poster presentations, and introduction of statistical concepts and approach to analyses, as well as epidemiologic and pathophysiologic reviews of the most common neurologic disorders associated with aging and thus likely to be studied. Our institution has the strongest track record of developing academic neurologists of anywhere worldwide, and such a short-term, intense program will build upon this wealth of resources through hands-on introductions to neurological research, comprehensive review of principles of research, and thus assure the best opportunity for these students to develop research careers in the field.

DESCRIPTION (provided by applicant): The Long Life Family Study (LLFS), established in 2005 in response to an NIA RFA, enrolled families enriched for exceptional longevity (EL), to discover factors that contribute to healthy aging and survival. From 2006 to 2009, LLFS enrolled 539 sibships (G1), their offspring (G2) and spouses (total 4,953). Comparison with a referent cohort reveals that LLFS families have strong exceptional clustering of EL. The G2 offspring have a variety of Healthy Aging Phenotypes (HAPs), defined as an unusually low age-specific prevalence of one or more specific conditions or risk factors, compared to population-based cohorts suggesting enrichment of shared (possibly genetic) protective effects in LLFS families. In the second funding period (2010-2013), we conducted a 2.5 million SNP GWAS (dbGaP phs000397); developed a high-throughput technique and sequenced ~450 candidate genes and replicated many variants and found additional ones associated with Healthy Aging Phenotypes (HAP) and longevity. 54% of LLFS G1 and 92% of G2 remain alive. Participant retention has been 94%. We now propose a third funding period to conduct a second in-person examination (V2) to prospectively study rates of change in HAPs with age and identify genetic and other factors contributing to HAPs and longevity. We hypothesize that EL and HAPs entail common and rare variants that individually have modest effects, but which in combinations strongly influence longevity and specific HAPs, and may only be detectable in family studies enriched for HAPs, such as LLFS. HAPs evaluated at the initial in-person visit show strong linkage peaks which are not explained by common haplotypes interrogated by GWAS (HLODs ranging from 6.0-45.1). These are likely driven by rare, lineage-private alleles that will only be found by sequencing specific families, and may point to important new biology. Specific Aim 1 is to conduct a second in-home examination on all surviving LLFS participants. Specific Aim 2 is to analyze cross-sectional and longitudinal phenotypes. The goal is to identify pathways for EL and HAPs by characterizing the shared and distinct LLFS phenotypes and environmental factors. We will characterize individual longitudinal patterns of HAPs to identify subgroups showing similar patterns and exceptional phenotypes. We will test whether these HAPs are heritable, and test for differences with internal and external referent groups. Specific Aim 3 is to find genes/variants associated with cross-sectional and longitudinal phenotypes using a) Whole Exome Sequencing to comprehensively search for coding variants associated with HAPs and EL and b) Targeted Regulatory Sequencing of regions under linkage peaks for HAPs in selected families showing the strongest linkage evidence. Specific Aim 4 is to replicate our genetic and epidemiological findings in other aging study cohorts. This study could lead to the discovery of pathways and potential therapeutic/prevention targets affecting HAPs and EL. A Data Management and Coordinating Center and 4 Field Centers comprise the major components of the LLFS. This renewal application is submitted by the Duke Uni./Uni. of Southern Denmark Field Center.

DESCRIPTION (provided by applicant): This proposal, entitled the Consortium for Alzheimer's Sequence Analysis (CASA) describes plans to analyze whole exome and whole genome sequence data generated from subjects with Alzheimer's disease (AD) and elderly normal controls. These data will be generated by the National Human Genome Institute Large-Scale Sequence Program. The goal of the planned analyses is to identify genes that have alleles that protect against or increase susceptibility to AD. This is a multiple PI proposal, a collaboration between five senior AD genetics investigators (Farrer, Haines, Mayeux, Pericak-Vance, Schellenberg). CASA has 4 cores and 3 projects. Core A is the Administrative core that will coordinate all aspects of CASA. Core B is the Analysis Statistics and Innovation core that will design and assist analysis by other cores/projects and devise novel methods of statistical analysis. Core C is that Data Management and Information Transfer Core that will implement analyses designed by Core B and the projects. Core C will provide high-performance computing for CASA. These three cores are mandated by FOA PAR-12-183. Core D is the In Silico Functional Genomics Core that will annotate AD-associated variants and perform pathway and interaction analyses. Project 1 will evaluate variants detected in the sequence data for association with AD to identify protective and susceptibility alleles. Project 2 will evaluate sequence data from multiplex AD families to identify variants associated with AD risk and protection, and evaluate variant co-segregation with AD. Project 3 will focus on structural variants (insertion-deletions, copy number variants, and chromosomal rearrangements). The project will use existing methods and develop and implement novel approaches for detecting structural variants. The projects and cores are highly interdependent. For example, structural variants identified by Project 3 will be integrated with single nucleotide AD-associated variants identified by Projects 1 and 2. Likewise variants identified by Project 1 will be tested in the family-based data sets. Core B will assist all projects in designing analyses and Core C will implement Project analyses. Core D will annotate and help interpret results from all projects.

GENETICS CORE SUMMARY The ADRC Human Genetics Core (HGC) was formed in a prior application to provide a centralized resource for the organization and analysis of genetic data for the entire ADRC, and to provide laboratory support for ADRC projects. The overall goal has been to facilitate the understanding of the associations between genetic variants and Alzheimer s disease or related neurodegenerative dementias, and to provide relevant information to investigators and patients and families. The HGC consists of components already well integrated into the Columbia ADRC. 1) A biorepository which includes data management to track biological sample inventories in coordination with the main ADRC database management core; 2) A statistical genetics and genetic epidemiology group to facilitate research involving genetic variables; 3) A board certified genetic counselor with expertise in neurodegenerative disorders available to help clinicians and affected families. Over the past funding cycle the HGC has created and maintained blood specimens (serum, plasma, DNA and immortalized cell lines (when requested) and cerebrospinal fluid) from all willing participants in the ADRC clinical core, Project 3 and all ADRC related studies. In the previous cycle we provided a source of DNA for planned genetic research in Project 3, and for the UDS and ADC collaborative projects, and the Alzheimer s Disease Genetic Consortium which was created to facilitate genetic research across all of the Alzheimer s Disease Centers. Dr. Mayeux, the HGC leader, is a senior co-investigator and member of the steering committee. He has played a major role in the design, and now the analyses, of the Alzheimer s Disease Sequencing Project, another project involving nearly all of the ADCs, epidemiological projects and other cohorts with well characterized cases and controls. The HGC prepared 353 samples from 68 families for the whole-genome sequencing experiment and over 4,000 samples for APOE genotyping. The investigators in this core also played major roles in the design of the Alzheimer s Disease Sequencing Project: Dr. Mayeux is leading the analysis of the family-based whole genome sequencing project of the Alzheimer s Disease Sequencing Project, Dr. Reitz, Co-Project Leader for Project 2 in this application, was involved in the design and will be involved in the analyses of the case-control whole exome project. Dr. Vardarajan, a co-investigator in this core was involved in the planning of the bioinformatics analyses for the family-based whole genome and the case-control whole exome studies as well as the structural variant analyses. The HGC has also been a resource for training of high school and college students in laboratory procedures such as sample preparation, extraction of DNA, banking of serum, plasma and cerebrospinal fluid.

? DESCRIPTION (provided by applicant): Over the past 15 years, we have focused our efforts primarily on Caribbean Hispanics from the Dominican Republic because the frequency of late-onset Alzheimer's disease (LOAD) is higher than in non-Hispanic whites and blacks, the families are large, there are relatively few founders, and there is strong evidence of inbreeding. In the previous funding cycle we met our recruitment goals, identified functional mutations in SORL1, initiated a large-scale genome wide association study (GWAS) and begun targeted re-sequencing and whole exome sequencing in Caribbean Hispanic families. Genetic analysis of LOAD has focused on common genetic variants using GWAS in unrelated patients and controls that may explain ~35% of the genetic variance of LOAD. Studies of rare variants are now beginning to emerge, particularly in family-based cohorts. As a result of preliminary work over the three previous funding cycles, we are in a very strong position for this renewal: 1) We have assembled a large cohort of unrelated Caribbean Hispanic LOAD cases and elderly controls and have identified several hundred families multiply affected by LOAD. 2) We investigated genome- wide (global burden) analyses of runs of homozygosity showing that the average run is significantly longer in cases than controls and stronger yet in familial LOAD, suggesting the existence of novel recessive LOAD gene(s). A locus-specific ROH analysis also revealed a genome-wide significant consensus region on chr9q34. 3) We have initiated a large scale GWAS of all families and a case-control cohort that will include over seven thousand subjects. A preliminary analysis has identified several putative associations with LOAD. 4) We have begun an analysis of data from a preliminary targeted re-sequencing of LOAD candidate genes, and whole exome sequencing (WES) in 115 members of 31 multiplex families. 5) Another 353 members of 67 multiplex families from this same cohort were included in the whole genome sequencing (WGS) study of the NIA/NHGRI Alzheimer's Disease Sequencing Project and analyses of these data are underway. Results of both analyses will be available to us near or just after the start date of this revised proposal. To take advantage of these resources and capitalize on our preliminary findings, we propose to use the results from the GWAS (Hispanic and non-Hispanic), analyses of runs of homozygosity, WES and WGS analyses from our population of Caribbean Hispanics, to conduct targeted re-sequencing in genes (loci), or pathways showing putative relationships to LOAD, followed by replication and validation genotyping, in silico bioinformatic and biophysical analyses of variant sequences identifying effects on gene structure and biological assays of gene function. The central hypothesis we are testing is that, as yet unidentified, common and rare genetic variants underlie the pathobiology of LOAD and can be found in large well-phenotyped multiplex families, cases and controls.

SUMMARY The primary goal of this project is to identify genetic modifiers of the PSEN1 mutation by studying a group of high risk PSEN1-G206A mutation carriers. If successful, we may be able to learn how these modifier variants may lower the risk of AD by delaying age at onset or slowing age-related memory decline. In 2001, we identified a founder mutation in PSEN1 (G206A) in family members from eight Caribbean Hispanic families with origins in Puerto Rico. The average age at onset with this mutation was unusually late (mean: 55.6 years) and was remarkably variable within as well as across families, ranging from 22-77 years. In this group of Puerto Rican families with multiple affected family members, this mutation is as prevalent as APOE ?4, but, unlike APOE ?4 carriers who have an increased risk of AD, most PSEN1 carriers will eventually develop Alzheimer disease (AD). To determine whether these PSEN1 mutation carrier families can be used to identify genetic modifiers, we performed a pilot whole exome sequencing (WES) study. Using 31 G206A carriers, we identified six candidate genes that may harbor variants that alter onset of AD in these families, and variants within these genes accounted for as much as 15-20 years differences in age at onset of AD [2]. We then observed that three out of six genes had SNPs that were associated with variable age at onset in individuals with late onset AD (LOAD), suggesting that these may be generalizable to LOAD, the most common form of AD. In the present study, we propose to perform state of the art whole genome sequencing (WGS) to identify genetic modifiers of age at onset or memory performance, while capitalizing on this unique high risk group with a founder mutation. To date, we have recruited and examined 75 extended EOAD families that have one or more individuals who carry the PSEN1-G206A mutation. Most of these individuals have in-depth phenotype data as well as GWAS data. In addition, we will have access to independent sets of unrelated Caribbean Hispanics as well as non-Hispanic Whites to examine how clinically relevant these variants are in the general populations. The short-term goal of this study is to identify genetic variants that modify the age at onset and/or memory performance in PSEN1-G206A carriers, but the long-term goal is to identify a potential therapeutic target(s) that might delay or prevent AD.

? DESCRIPTION (provided by applicant): Alzheimer disease (AD) is the leading cause of dementia in the elderly and occurs in all ethnic and racial groups. A multitude of genetic studies in AD have identified multiple AD associated genes and loci, but a large portion of the genetic influence on AD remain unknown. The Alzheimer Disease Sequencing Project (ADSP) will use large-scale sequencing efforts to increase our knowledge about the genetic variation that influences AD, particularly rare genetic variants that enhance AD risk or protect against AD. Substantially underrepresented in these efforts, however, is the generalization of current and future findings in African Americans (AA). AA have a higher prevalence of dementia than non-Hispanic Whites (NHW). Despite steady improvement in the overall health of the U.S. population, individuals within these underserved groups continue to be vulnerable to lapses in care and are at increased risk for health problems. Health disparities have had an especially profound negative effect on the overall health of AA. AA have disproportionally higher health-risk factors, limited access to health services, and ultimately poorer health outcomes and life expectancies than NHW. The determinants of the health disparities seen in AA are many, including public health policy, clinical practices, and social, economic, cultural and/or language factors. One promising avenue for reducing health disparities is the use of precision medicine to improve disease prediction, prevention, diagnosis, and treatment. However, genomic medicine relies on participation from diverse populations in both research and clinical applications. Through this application, we will address this important issue by conducting genomic studies of AD in AA. In response to RFA AG-16-002, we are proposing a set of experiments that will complement and extend the activities and results of the ADSP Discovery and Replication phases, thereby addressing the issue of health disparities in AD research. Specifically we propose a family-based study in AA that parallels the family-based efforts in the ADSP Discovery phase and that will enhance and extend current ADSP efforts to a broader AD community. Specifically, we will 1) Expand our existing AA family dataset; 2.) Generalize and refine ADSP risk and protective loci in familial AA AD. 3.) Prioritize variants by admixture mapping and bioinformatics analysis and 4.) Perform multi-locus analyses providing insight into functional implications of the known risk and protective loci and identifying possible additional genic targets. Our overall goal is to identify targets for therapeutic development that will either prevent or significantly delay the onset of AD.

PROJECT SUMMARY Clinical criteria for late-onset Alzheimer's disease (LOAD) excludes individuals with ?substantial cerebrovascular disease? but as many as up 70% of patients with LOAD have cerebrovascular pathology in addition to amyloid plaques and neurofibrillary tangles at postmortem examination. Whether cerebrovascular damage represents a cause of LOAD, an additional brain insult or whether cerebrovascular pathology interacts with genetic factors remains unknown. The Washington Heights and Inwood, Columbia Aging Project is a large, epidemiological investigation of dementia in a multi-ethnic community in northern Manhattan, New York. The investigators have estimated the ethnic and sex-specific rates of late onset Alzheimer's disease and mild cognitive impairment, conducted longitudinal assessments of cognitive performance, health and lifestyle factors, mood, ADLs, blood pressure, anthropometry, several blood-based biomarkers, genome wide association studies (GWAS), structural MRI and is in the process of completing whole exome sequencing (WES) in 4100 individuals. We intend to take advantage of this multi-ethnic, longitudinal cohort to test hypotheses concerning how genetic variants, cardiovascular and cerebrovascular risk factors and cerebrovascular disease predispose to LOAD and whether these relationships differ by ethnic group. We intend to address three critical questions: 1) Do genetic variants influence both LOAD and cardio-cerebrovascular risk factors independently or do they interact? 2) Do cardio- cerebrovascular risk factors lead to cerebrovascular pathology, present on brain MRI, which in turn simply lowers the threshold for clinical onset of dementia? 3) Are genetic variants unrelated to cardio-cerebrovascular risk factors and simply exacerbate the effects of cerebrovascular pathology leading to LOAD? Or could the reverse be true, that silent cerebrovascular disease exacerbates the effects of genetic variants on LOAD risk? LOAD and cerebrovascular disease are likely to be part of a continuum in which the onset and clinical manifestations of dementia are jointly determined. Thus, investigating the relationship between genes harboring variants, vascular risk factors, cerebrovascular disease and LOAD would advance our understanding of this complex disease process and will help develop potential targets for treatments or preventive measures that are more precise for the individual patient.

The National Institute of Aging Late Onset Alzheimer?s Disease Family Based Study (NIA-LOAD FBS) began in 2003, starting a trend of greater cooperation and sharing of clinical and biological resources among researchers. To date, a total of 1,454 multiplex late onset AD (LOAD) families have been recruited with 8,543 family members clinically assessed and DNA sampled. We have also recruited 1,030 controls. Genome-wide SNP arrays have been generated on 5,428 individuals, exome chip genotyping on 1,278 individuals, whole exome sequencing in 1,484 and whole genome in 928 family members and controls. The conversion rate of to LOAD among unaffected relatives in the NIA-LOAD FBS is three-fold higher than would be expected among individuals of similar age (see #67 Bibliography). All of these data have been placed in the public domain in NIAGADS and dbGaP. The NIA-LOAD FBS is widely used in Alzheimer disease genetics with 79 high level publications to support this claim (Bibliography). The NIA-LOAD FBS provides an excellent opportunity to improve our understanding of the clinical and biological impact of genetic variation in the elderly. Phenotypic information is continually updated in these families by regular cognitive evaluations and autopsy at the time of death to confirm the diagnosis of LOAD. We have begun to recruit additional family members with a particular emphasis on the offspring generation. We have been able to bank brain tissue from family members creating one of the largest collections of brain tissues for familial LOAD. We will now expand biological sampling to include RNA and peripheral blood mononuclear cells in selected families. As additional genes and variants are identified, the members of the NIA LOAD Family Study will again play a central role as we explore: What is the impact of these risk and protective variants on disease risk? Are the genetic variants highly penetrant? What is the risk of developing LOAD in offspring? Can the presence of variants be used for stratification of patients into specific subtypes for clinical trials? Can the family data be used to identify novel biomarkers of disease risk, age at onset onset or progression? The NIA-LOAD FBS dataset is uniquely poised to address these clinical and biological questions because of its large size, rigorous ascertainment criteria, standardized clinical assessment and lack of restriction to specific mutations. Our efforts have made it easy and seamless for the genetic data to be shared, allowing even more researchers to obtain the data and samples collected as part of the NIA-LOAD FBS for research studies. This is by far the largest collection of LOAD families available in the world. Virtually every major genetic study of Alzheimer?s disease has included patients and controls from the NIA-LOAD FBS dataset. The availability of dense phenotypic and genetic data will also position the NIA-LOAD FBS in to determine the impact of variants identified in whole genome and whole exome sequencing projects currently underway.

PROJECT SUMMARY The Alzheimer?s Disease Sequencing Project (ADSP) is a national sequencing initiative focused on identifying genetic risk and protective factors for Alzheimer?s Disease (AD) in an effort to identify new pathways for prevention and new targets for drug development. The projects? discovery phase included whole exome sequencing (WES) of 10,914 unrelated cases (N=5,778) and controls (N=5,136) and whole genome sequencing (WGS) of 1,019 familial samples. A majority of these samples are non-Hispanic white (NHW) in origin, making the addition of ethnically diverse samples to the study critical to identification of both shared and novel genetic risk factors for AD between populations. This ethnic diversity was emphasized in the ?ADSP Follow-Up Study (FUS) Phase? planning stage with a directive that additional existing cohorts with unrelated AD cases that ?encompass the richest possible ethnic diversity? be given the highest priority for inclusion. To fulfill the goals of this RFA and this FUS Phase Mandate, this proposal identifies seven existing elderly cohorts of African-American (AA) and pan-HI ancestry with a total of 10,430 samples (N=2,322 AA AD cases and 1,843 AA controls and 2,928 Hispanic AD cases and 2,875 Hispanic controls) for WGS and processing in collaboration with existing NIH-funded AD infrastructure. Combining these cohorts with existing African America (AA) and Hispanic (HI) sequencing from the Washington Heights-Hamilton Heights-Inwood Community Aging Project (WHICAP), the Alzheimer?s Disease Genetics Consortium (ADGC) and the ADSP will provide large ethnically diverse datasets for both validation of ADSP discovery phase findings and discovery of novel risk and/or protective variants for AD. Importantly, these data will allow for admixture mapping, a powerful method of gene mapping for diseases that show differential risk by ancestry, by comparing allele frequency differences between populations. They will also become an invaluable resource for the AD research community at-large, and will help to address the health disparities that contribute to AA and HI populations having higher rates of AD than NHW. Thus, we will address these important issues by creating a large dataset of AA and pan-HI AD cases and controls for study. Specifically we propose to: 1) increase the ethnic diversity of the ADSP by assembling samples from existing cohorts with AA and HI AD cases and controls; 2) collaborate with the National Cell Repository for Alzheimer?s Disease (NCRAD) in assemblage, storage, and distribution of DNA on these cohorts; 3) generating genome-wide SNP array data and WGS for all collected samples; and 4) collaborate with the NIA Genetics of Alzheimer?s Disease Data Storage Site (NIAGADS) and The Genome Center for Alzheimer?s Disease (GCAD) in processing, quality controls, storage and distribution of the final datasets. Our overall goal is to enhance the discovery of AD risk factors by facilitating research on AD in ethnically diverse datasets.

Project summary The Department of Neurology at Columbia University Medical Center serves as a rich site for multidisciplinary neurological research, with particular focus on the aging nervous system and Alzheimer?s disease and Related Dementias (AD and ADRD). This proposal seeks to continue funding for positions for 20 preclinical students participating in the Brief Research in Aging and Interdisciplinary Neurosciences (BRAIN) program each summer. For the BRAIN program, we have developed a comprehensive approach to develop a formal research program for predoctoral students early in developing careers in biomedical, behavioral and clinical research. The work is collaboratively approached through brief but intensive mentored summer research training experiences for these students. The research training provides opportunities in basic, behavioral and clinical research through ongoing research in the fields of basic neuroscience, neuropathology, neurogenetics, neuropsychology, epidemiology, and clinical trials, with a focus on Alzheimer?s disease and Related Dementias, aging-related motor neuron disease, stroke, and epilepsy, as well as neurologic clinical trials treating patients with these disorders. Methods for inclusion of biological and cognitive markers of neurological disease progression, such as cerebral amyloid and tau, structural brain imaging, as well as assessment of memory, executive function, and other cognitive domains are embedded within the training curriculum. In addition, a comprehensive structured research education curriculum is delivered over the course of the intense research experience, with topics including good clinical practice, basic research methodologies, introductions to abstract authorship and poster presentations, and introduction of statistical concepts and approach to analyses, as well as epidemiologic and pathophysiologic reviews of the most common neurologic disorders such as Alzheimer?s disease. Our institution has the strongest track record of developing academic neurologists of anywhere worldwide, and this short-term, intense program builds upon this wealth of resources through hands-on introductions to neurological research, comprehensive review of principles of research, and thus assures the best opportunity for these students to develop research careers in the field of disorders of the aging nervous system including Alzheimer?s disease.

Late onset Alzheimer?s disease (LOAD) with onset after age 60 years is the most frequent neurodegenerative disease affecting all ethnic and racial groups. Although the causes remain unclear, studies in case-control cohorts and families with multiple affected members support a genetic etiology for LOAD. To date, large genome- wide association (GWAS) and sequencing studies of LOAD have been carried out mostly in non-Hispanic White populations, and have so far identified over 21 loci associated with increased risk of LOAD. The same loci have also been identified in ethnically diverse populations (Caribbean-Hispanics and African-Americans), some of them with even large genetic effects such as ABCA7 in African Americans. Novel genes were also discovered by GWAS in non-White populations (e.g. FBXL7 in Caribbean Hispanics), ultimately proving their potential to reveal novel pathways or mechanisms underlying LOAD risk and prevention. Data from the 10/66 Dementia Research Group estimates the prevalence of dementia in Mexico to be ~7.3% for people 60 years of age and older, and is projected to increase up to 400% by 2050. Despite this high prevalence, Mexican population is underrepresented in genetic studies. To our knowledge, other than APOE gene effect on the disease, there are few genetic investigations of LOAD among individuals of Mexican ancestry in the United States or elsewhere. The underrepresentation of individuals of Mexican and other ancestries in genetic and translational research ultimately affects the possibility of leveraging their contribution on clinical genomic applications such as genetic testing, counseling and ultimately precision medicine approaches. We aim to define risk and protective genetic loci on LOAD and related dementias in individuals with Mexican ancestry. To that end, the proposed study will establish the first large-scale investigation of the genetic bases for LOAD and related disorders among individuals of Mexican ancestry. We propose to build on an existing unique and outstanding cohort, the ?Mexican Health and Aging Study? (MHAS); this is a prospective national longitudinal study, which began in 2001, has aimed to evaluate the impact of age-related diseases among Mexican adults living in both urban and rural settings. Over a 20-years follow-up, MHAS has collected demographic and clinical data (including cognitive assessment) in 15,000 individuals of Mexican ancestry aged 50 and older. Specifically we propose to: 1) obtain saliva in all MHAS participants over age 60 years who will be interview in the fall of 2018 as part of the 5th MHAS follow-up wave, and perform a genome wide association study (GWAS) and admixture mapping for dementia using DNA extracted from ~10,000 participants. 2) validate clinical dementia classification with an extended cognitive Mex-Cog battery in a sub-sample of ~2500 MHAS participants 60 years of age or older to be consistent with NIA-Alzheimer Association recommendations; this will also be used to validate the clinical diagnoses used for the GWAS in the previous aim. 3) perform whole genome sequencing in the subsample of MHAS subjects with validated diagnosis.

PROJECT SUMMARY The Alzheimer's Disease Sequencing Project (ADSP) is a national sequencing initiative focused on identifying genetic risk and protective factors for AD. The projects' discovery phase includes whole exome sequencing (WES) of 10,061 unrelated non-White Hispanic (NHW) cases (N=5,096) and controls (N=4,965), and whole genome sequencing (WGS) of 584 NHW and Hispanic familial samples. The 'Discovery Extension Phase' of the project added WGS on ~430 additional familial samples. An initial 'Follow-Up Study (FUS)' Phase focused on examining candidate variants from the discovery phase, and identification of novel variants through combined analysis of diverse datasets is ongoing and focuses on additional existing cohorts with unrelated AD cases that 'encompass the richest possible ethnic diversity' as well as highly valuable set of autopsy confirmed cases and controls. In total we have already included in FUS over 14000 samples for sequencing including >2800 autopsy confirmed cases and controls, >6800 Hispanic (HI) cases and controls and > 5790 African American (AA) cases and controls. In this FUS2 application, we are proposing sequencing of an additional 4243 samples that will both increase our power to find effects but will also enhance our analysis by inclusion of several rich and unique sample sets. Additionally, these datasets will become an invaluable resource for the AD research community at-large. In summary ADSP will provide large ethnically diverse as well as unique datasets for both validation and generalization of ADSP discovery phase findings and discovery of novel risk and protective variants/genes for late onset AD (LOAD). Additionally, these datasets will become an invaluable resource for the AD research community at-large. Specifically we propose to: 1. Increase the diversity and further enrich the clinical phenotype data of the ADSP including data sets targeted to find protective effects through assembling samples from existing cohorts from unique populations that fulfill this goal. 2. Collaborate with the National Cell Repository for AD (NCRAD) in assembling DNA, blood and brain tissue on these existing cohorts, which will serve as a central resource for the AD research community. 3. Generate genome-wide SNP array data through the John P. Hussman Institute (HIHG) Center for Genome Technology (CGT) and whole genome sequencing data through the Uniformed Services University of the Health Sciences (USUHS) for all collected samples 4. Collaborate with NIA Genetics of AD Data Storage Site (NIAGADS), the Genome Center for AD (GCAD) and the University of Pennsylvania and the HIHG Center for Genetic Epidemiology and Statistical Genetics Quality Control Teams in processing, storage and dissemination of final data sets. Our overall goal is to enhance the discovery of AD risk and protective factors by facilitating research on AD in ethnically diverse and phenotypically rich datasets.

ABSTRACT For 25 years, we have investigated the genetic bases of familial and sporadic Alzheimer?s disease (AD) among Caribbean Hispanics in the US and in the Dominican Republic, contributing samples and data to the Alzheimer?s Disease Genetics Consortium and the Alzheimer?s Disease Sequencing Project. For this new proposal, we intend to integrate the genetic analyses of AD in Caribbean Hispanics with deep molecular phenotyping: epigenomics, transcriptomics, proteomics and metabolomics using whole blood, plasma, cerebrospinal fluid and brain tissue where possible. Multi-omics data generated in this minority population will be used to understand the effects of gene variants on disease, clarify the affected proteins and pathways that underlie AD and for comparison to results obtained from similar studies in white, non-Hispanic populations such as Accelerated Medicines Partnership ? Alzheimer?s Disease. Compared with non-Hispanics, we have shown that Caribbean Hispanics are three times more likely to develop AD by age 75 years. If they have family members with AD their risk is five times higher. From the study entitled, ?Estudio Familiar Investigar Genetica de Alzheimer? (EFIGA, RF1AG01543) we have clinical information and biological samples in 701 families multiply affected by AD, including 5,932 individuals of which 304 families (43%) have three or more affected relatives and 1,874 individuals with sporadic AD and 2,739 healthy controls. We have begun recruiting members of the Caribbean Hispanic Religious Orders aged 60 years and older who consent to blood sampling for DNA and plasma, lumbar puncture for cerebrospinal fluid and autopsy at death. Our systematic genetic analyses in CH have yielded putative variants in ABCA7, BIN1, CD2AP, CLU, CR1, EPHA1, MS4A4A/MS4A6A, PICALM, SORL1, PINX1 and SRCAP, each of which has been replicated. To covert these genetic findings into meaningful applications to AD we now want to focus our efforts on the relationships between the genetic variants and epigenomics, transcriptomics, proteomics, metabolomics. From the existing cohorts of genetically characterized individuals we will assemble a new multi-omics cohort. This multi-omics cohort of 1,000 individuals will identify systems-level alterations in AD and will provide insight into the mechanisms underlying genetic variants, assist in identifying disease pathways, putative protein-protein interactions and downstream metabolites that can be used to inform preclinical work, develop biomarkers and eventually therapeutic targets for drug discovery. The overarching goal is to use a genetic variant-centered, environmentally inclusive integration of multiple omics layers to identify specific causal genes and investigate how they may perturb pathways leading to disease.

ABSTRACT. The analysis of cerebrospinal fluid (CSF) and molecular PET biomarkers of A? and phospho-tau combined with MRI assessment of global and regional neurodegeneration led to the development of the ?A/T/N? classification scheme for Alzheimer's disease (AD) that was intended to add precision to the diagnosis for clinical purposes, therapeutic trials and regulatory agencies. For observational epidemiological research the widespread use of these types of biomarkers is not possible because of the expense and limited access to cyclotrons necessary for molecular imaging and the difficulty in obtaining CSF in large studies. Further, it is clear that the relationship of biomarker values to clinical diagnoses can also differ by age, sex and race/ethnic group, and few studies have included diverse cohorts, representative of the population in the US. The advent of newly- established, blood-based biomarkers (A?40, A?42, p-tau217, neurofilament light chain or NFL) combined with brain MRI provides an opportunity to investigate the application of ?A/T/N biomarker profile? in community-based, observational study, and create endophenotypes that can be used to identify genetic susceptibility. The Washington Heights, Inwood Columbia Aging Project (WHICAP) study is one of the few cohorts where the newly established blood-based biomarkers and well-established neuroimaging biomarkers for AD can be used to investigate a blood-based ?A/T/N biomarker profile? across race/ethnic groups and by age and sex. Amyloid (plasma A?40 and A?42), Tau (plasma total tau and p-tau217), and Neurodegeneration (plasma neurofilament light [NfL], and MRI (brain volumes and cortical thickness) will be assessed in a longitudinal, multi-ethnic community-based elderly cohort (24% white non-Hispanic, 28% African American, 48% Caribbean Hispanic). The cohort has been genetically characterized, and has stored DNA, sera, and plasma. The effects of cerebrovascular disease ?V? and psychosocial factors will also be investigated as potential modulators of the ?A/T/N biomarker profile?. We will use publicly available genetic data in African American, Caribbean Hispanic and non-Hispanic white participants that included the WHICAP cohort to create ethnic-specific polygenic risk scores (ePRS). This will allow the identification of variants associated with the endophenotypes underlying the ?A/T/N biomarker profile? and augment the ePRS association with the clinical diagnoses of AD. We will maintain longitudinal follow-up of the WHICAP cohort, adding participants only to account for attrition, collecting whole blood for plasma and sera, ascertaining psychosocial and biomedical risk and protective factors and obtaining structural MRI measures at least twice in participants over a four-year period. The overall goals of this project are to: 1) investigate variability in blood-based biomarkers and MRI measures in the ?A/T/N biomarker profile? as it applies to clinical diagnoses in a multi-ethnic cohort; 2) investigate blood-based biomarkers as endophenotypes in genetic analyses for earlier detection and diagnosis of AD; 3) investigate how cerebrovascular disease and psychosocial factors modulate the use of blood-based and MRI biomarkers.