Eleven susceptibility loci for late-onset Alzheimer’s disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer’s disease cases and 37,154 controls. In stage 2,11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer’s disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10−8) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer’s disease.

APOE ε4, the most significant genetic risk factor for Alzheimer disease (AD), may mask effects of other loci. We re-analyzed genome-wide association study (GWAS) data from the International Genomics of Alzheimer’s Project (IGAP) Consortium in APOE ε4+ (10,352 cases and 9,207 controls) and APOE ε4− (7,184 cases and 26,968 controls) subgroups as well as in the total sample testing for interaction between a SNP and APOE ε4 status. Suggestive associations (P<1x10−4) in stage 1 were evaluated in an independent sample (stage 2) containing 4,203 subjects (APOE ε4+: 1,250 cases and 536 controls; APOE ε4-: 718 cases and 1,699 controls). Among APOE ε4− subjects, novel genome-wide significant (GWS) association was observed with 17 SNPs (all between KANSL1 and LRRC37A on chromosome 17 near MAPT) in a meta-analysis of the stage 1 and stage 2 datasets (best SNP, rs2732703, P=5·8x10−9). Conditional analysis revealed that rs2732703 accounted for association signals in the entire 100 kilobase region that includes MAPT. Except for previously identified AD loci showing stronger association in APOE ε4+ subjects (CR1 and CLU) or APOE ε4− subjects (MS4A6A/MS4A4A/ MS4A6E), no other SNPs were significantly associated with AD in a specific APOE genotype subgroup. In addition, the finding in the stage 1 sample that AD risk is significantly influenced by the interaction of APOE with rs1595014 in TMEM106B (P=1·6x10−7) is noteworthy because TMEM106B variants have previously been associated with risk of frontotemporal dementia. Expression quantitative trait locus analysis revealed that rs113986870, one of the GWS SNPs near rs2732703, is significantly associated with four KANSL1 probes that target transcription of the first translated exon and an untranslated exon in hippocampus (P≤1.3x10−8), frontal cortex (P≤1.3x10−9), and temporal cortex (P≤1.2x10−11). Rs113986870 is also strongly associated with a MAPT probe that targets transcription of alternatively spliced exon 3 in frontal cortex (P=9.2x10−6) and temporal cortex (P=2.6x10−6). Our APOE-stratified GWAS is the first to show GWS association for AD with SNPs in the chromosome 17q21.31 region. Replication of this finding in independent samples is needed to verify that SNPs in this region have significantly stronger effects on AD risk in persons lacking APOE ε4 compared to persons carrying this allele, and if this is found to hold, further examination of this region and studies aimed at deciphering the mechanism(s) are warranted.

To estimate the allele frequency of C9orf72 (G 4 C 2 ) repeats in amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), Alzheimer disease (AD), and Parkinson disease (PD).Design: The number of repeats was estimated by a 2-step genotyping strategy. For expansion carriers, we sequenced the repeat flanking regions and obtained APOE genotypes and MAPT H1/H2 haplotypes.Setting: Hospitals specializing in neurodegenerative disorders. Subjects:We analyzed 520 patients with FTLD, 389 patients with ALS, 424 patients with AD, 289 patients with PD, 602 controls, 18 families, and 29 patients with PD with the LRRK2 G2019S mutation.Main Outcome Measure: The expansion frequency.Results: Based on a prior cutoff (Ͼ30 repeats), the expansion was detected in 9.3% of patients with ALS, 5.2% of patients with FTLD, and 0.7% of patients with PD but not in controls or patients with AD. It was significantly Author Affil the end of th Author Affiliations are listed at the end of this article.

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This study aimed to evaluate the association between follicle-stimulating hormone (FSH) hormone efficacy and FSHR, CYP19, ESR1 and ESR2 genes using single nucleotide polymorphism analyses. One hundred and seventy women with conserved ovarian function undergoing controlled ovarian stimulation (COS) with daily exogenous recombinant FSH administration. Women were categorized as poor responders to FSH (three or less ovarian follicles observed at the end of cycle) or normal responders (more than three follicles). The outcome is the number of normal/poor responders as defined by the number of follicles obtained during COS. The DNA markers studied are located in genes related to the FSH mechanism of action (FSH receptor, CYP19 aromatase and oestrogen receptors alpha and beta genes). We conducted an association study between the COS outcome and selected DNA markers using two-point and multi-locus genetic association studies. Genotype pattern tracking in extreme phenotypes and multi-locus analysis using Sumstat and PM algorithms provided significant evidences of genetic interaction between FSHR, ESR1 and ESR2 markers in relation to COS outcome (P = 0.0015). Our results support the hypothesis that a discrete set of genes, related to the FSH hormone mechanism of action, controls the ovarian response to FSH in humans. An oligogenic model including specific FSHR, ESR1 and ESR2 genotype patterns may partially explain the poor response to FSH hormone during controlled ovarian stimulation treatments. The existence of genetic heterogeneity is also suspected.