Joseph H. Lee

The neuronal sortilin-related receptor SORL1 is genetically associated with Alzheimer disease

The recycling of the amyloid precursor protein (APP) from the cell surface via the endocytic pathways plays a key role in the generation of amyloid β peptide (Aβ) in Alzheimer disease. We report here that inherited variants in the SORL1 neuronal sorting receptor are associated with late-onset Alzheimer disease. These variants, which occur in at least two different clusters of intronic sequences within the SORL1 gene (also known as LR11 or SORLA) may regulate tissue-specific expression of SORL1. We also show that SORL1 directs trafficking of APP into recycling pathways and that when SORL1 is underexpressed, APP is sorted into Aβ-generating compartments. These data suggest that inherited or acquired changes in SORL1 expression or function are mechanistically involved in causing Alzheimer disease.

Large-scale meta-analysis of genome-wide association data identifies six new risk loci for Parkinson's disease

We conducted a meta-analysis of Parkinsons disease genome-wide association studies using a common set of 7,893,274 variants across 13,708 cases and 95,282 controls. Twenty-six loci were identified as having genome-wide significant association; these and 6 additional previously reported loci were then tested in an independent set of 5,353 cases and 5,551 controls. Of the 32 tested SNPs, 24 replicated, including 6 newly identified loci. Conditional analyses within loci showed that four loci, including GBA, GAK-DGKQ, SNCA and the HLA region, contain a secondary independent risk variant. In total, we identified and replicated 28 independent risk variants for Parkinsons disease across 24 loci. Although the effect of each individual locus was small, risk profile analysis showed substantial cumulative risk in a comparison of the highest and lowest quintiles of genetic risk (odds ratio (OR) = 3.31, 95% confidence interval (CI) = 2.55–4.30; P = 2 × 10−16). We also show six risk loci associated with proximal gene expression or DNA methylation.

Prevalence of Chronic Medical Conditions in Adults with Mental Retardation: Comparison with the General Population.

We interviewed caregivers and reviewed medical records of 278 adults with mental retardation with and without Down syndrome, 45 to 74 years of age. Standardized morbidity ratios were used to compare frequency of medical disorders in these adults to frequency in the general population. In adults with mental retardation, the frequency of common age-related disorders was comparable to that in the general population, but there was an increased frequency of thyroid disorders, nonischemic heart disorders, and sensory impairment. Surveillance of health status and increased access to health care for screening and treatment of age-related disorders that are more frequent in adults with mental retardation would be important to prevent the development or delay the impact of these conditions and to promote healthy aging.

Genome-Wide Association of Familial Late-Onset Alzheimer's Disease Replicates BIN1 and CLU and Nominates CUGBP2 in Interaction with APOE

Late-onset Alzheimers disease (LOAD) is the most common form of dementia in the elderly. The National Institute of Aging-Late Onset Alzheimers Disease Family Study and the National Cell Repository for Alzheimers Disease conducted a joint genome-wide association study (GWAS) of multiplex LOAD families (3,839 affected and unaffected individuals from 992 families plus additional unrelated neurologically evaluated normal subjects) using the 610 IlluminaQuad panel. This cohort represents the largest family-based GWAS of LOAD to date, with analyses limited here to the European-American subjects. SNPs near APOE gave highly significant results (e.g., rs2075650, p = 3.2×10−81), but no other genome-wide significant evidence for association was obtained in the full sample. Analyses that stratified on APOE genotypes identified SNPs on chromosome 10p14 in CUGBP2 with genome-wide significant evidence for association within APOE ε4 homozygotes (e.g., rs201119, p = 1.5×10−8). Association in this gene was replicated in an independent sample consisting of three cohorts. There was evidence of association for recently-reported LOAD risk loci, including BIN1 (rs7561528, p = 0.009 with, and p = 0.03 without, APOE adjustment) and CLU (rs11136000, p = 0.023 with, and p = 0.008 without, APOE adjustment), with weaker support for CR1. However, our results provide strong evidence that association with PICALM (rs3851179, p = 0.69 with, and p = 0.039 without, APOE adjustment) and EXOC3L2 is affected by correlation with APOE, and thus may represent spurious association. Our results indicate that genetic structure coupled with ascertainment bias resulting from the strong APOE association affect genome-wide results and interpretation of some recently reported associations. We show that a locus such as APOE, with large effects and strong association with disease, can lead to samples that require appropriate adjustment for this locus to avoid both false positive and false negative evidence of association. We suggest that similar adjustments may also be needed for many other large multi-site studies.

Shorter telomeres are associated with mortality in those with APOE ϵ4 and dementia

Reduced telomere length may be a marker of biological aging. We hypothesized that telomere length might thus relate to increased risk for dementia and mortality.

Identification of Novel Loci for Alzheimer Disease and Replication of CLU, PICALM, and BIN1 in Caribbean Hispanic Individuals

OBJECTIVES To identify novel loci for late-onset Alzheimer disease (LOAD) in Caribbean Hispanic individuals and to replicate the findings in a publicly available data set from the National Institute on Aging Late-Onset Alzheimers Disease Family Study. DESIGN Nested case-control genome-wide association study. SETTING The Washington Heights-Inwood Columbia Aging Project and the Estudio Familiar de Influencia Genetica de Alzheimer study. PARTICIPANTS Five hundred forty-nine affected and 544 unaffected individuals of Caribbean Hispanic ancestry. INTERVENTION The Illumina HumanHap 650Y chip for genotyping. MAIN OUTCOME MEASURE Clinical diagnosis or pathologically confirmed diagnosis of LOAD. RESULTS The strongest support for allelic association was for rs9945493 on 18q23 (P=1.7×10(-7)), but 22 additional single-nucleotide polymorphisms (SNPs) had a P value less than 9×10(-6) under 3 different analyses: unadjusted and stratified by the presence or absence of the APOE ε4 allele. Of these SNPs, 5 SNPs (rs4669573 and rs10197851 on 2p25.1; rs11711889 on 3q25.2; rs1117750 on 7p21.1; and rs7908652 on 10q23.1) were associated with LOAD in an independent cohort from the National Institute on Aging Late-Onset Alzheimers Disease Family Study. We also replicated genetic associations for CLU, PICALM, and BIN1. CONCLUSIONS Our genome-wide search of Caribbean Hispanic individuals identified several novel genetic variants associated with LOAD and replicated these associations in a white cohort. We also replicated associations in CLU, PICALM, and BIN1 in the Caribbean Hispanic cohort.

Meta-analysis of the Association Between Variants in SORL1 and Alzheimer Disease

OBJECTIVE To reexamine the association between the neuronal sortilin-related receptor gene (SORL1) and Alzheimer disease (AD). DESIGN Comprehensive and unbiased meta-analysis of all published and unpublished data from case-control studies for the SORL1 single-nucleotide polymorphisms (SNPs) that had been repeatedly assessed across studies. SETTING Academic research institutions in the United States, the Netherlands, Canada, Belgium, the United Kingdom, Singapore, Japan, Sweden, Germany, France, and Italy. PARTICIPANTS All published white and Asian case-control data sets, which included a total of 12,464 cases and 17,929 controls. MAIN OUTCOME MEASURES Alzheimer disease according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) and the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimers Disease and Related Disorders Association (now known as the Alzheimers Association). RESULTS In the white data sets, several markers were associated with AD after correction for multiple testing, including previously reported SNPs 8, 9, and 10 (P < .001). In addition, the C-G-C haplotype at SNPs 8 through 10 was associated with AD risk (P < .001). In the combined Asian data sets, SNPs 19 and 23 through 25 were associated with AD risk (P < .001). The disease-associated alleles at SNPs 8, 9, and 10 (120,873,131-120,886,175 base pairs [bp]; C-G-C alleles), at SNP 19 (120,953,300 bp; G allele), and at SNPs 24 through 25 (120,988,611 bp; T and C alleles) were the same previously reported alleles. The SNPs 4 through 5, 8 through 10, 12, and 19 through 25 belong to distinct linkage disequilibrium blocks. The same alleles at SNPs 8 through 10 (C-G-C), 19 (G), and 24 and 25 (T and C) have also been associated with AD endophenotypes, including white matter hyperintensities and hippocampal atrophy on magnetic resonance imaging, cerebrospinal fluid measures of amyloid β-peptide 42, and full-length SORL1 expression in the human brain. CONCLUSION This comprehensive meta-analysis provides confirmatory evidence that multiple SORL1 variants in distinct linkage disequilibrium blocks are associated with AD.

Association between SORL1 and Alzheimer's disease in a genome-wide study.

Several studies have reported an association of Alzheimers disease (AD) with polymorphic markers in SORL1. Data from a recently published genome-wide association study in AD have been made publicly available. We tested the association of AD with SORL1 in this dataset (Translational Genomics Research Institute; TGEN), which included 31 SORL1 single nucleotide polymorphisms (SNPs), eight of which overlapped the original study. Six SNPs, near the 3′ region of SORL1 containing SNPs which were strongly associated with AD in previous studies, showed significant association in the TGEN dataset. These results provide an independent replication of the association between AD and SORL1.

SORCS1 alters amyloid precursor protein processing and variants may increase Alzheimer's disease risk

Sorting mechanisms that cause the amyloid precursor protein (APP) and the β‐secretases and γ‐secretases to colocalize in the same compartment play an important role in the regulation of Aβ production in Alzheimers disease (AD). We and others have reported that genetic variants in the Sortilin‐related receptor (SORL1) increased the risk of AD, that SORL1 is involved in trafficking of APP, and that underexpression of SORL1 leads to overproduction of Aβ. Here we explored the role of one of its homologs, the sortilin‐related VPS10 domain containing receptor 1 (SORCS1), in AD.

Analyses of the National Institute on Aging Late-Onset Alzheimer's Disease Family Study: Implication of Additional Loci

OBJECTIVE To identify putative genetic loci related to the risk of late-onset Alzheimer disease (LOAD). DESIGN Linkage analysis and family-based and case-control association analyses from a genomewide scan using approximately 6000 single-nucleotide polymorphic markers at an average intermarker distance of 0.65 cM. SETTING The National Institute on Aging Genetics Initiative for Late-Onset Alzheimers Disease (NIA-LOAD) was created to expand the resources for studies to identify additional genes contributing to the risk for LOAD. PARTICIPANTS We investigated 1902 individuals from 328 families with LOAD and 236 unrelated control subjects. MAIN OUTCOME MEASURES Clinical diagnosis of LOAD. RESULTS The strongest overall finding was at chromosome 19q13.32, confirming the effect of the apolipoprotein E gene on LOAD risk in the family-based and case-control analyses. However, single-nucleotide polymorphisms at the following loci were also statistically significant in 1 or more of the analyses performed: 7p22.2, 7p21.3, and 16q21 in the linkage analyses; 17q21.31 and 22q11.21 in the family-based association analysis; and 7q31.1 and 22q12.3 in the case-control analysis. Positive associations at 7q31.1 and 20q13.33 were also significant in the meta-analysis results in a publicly available database. CONCLUSIONS Several additional loci may harbor genetic variants associated with LOAD. This data set provides a wealth of phenotypic and genotypic information for use as a resource in discovery and confirmatory research.