NG00036 - IGAP Summary Statistics- Lambert et al. (2013)


The International Genomics of Alzheimer's Project (IGAP) is releasing the summary results data from the 2013 meta-analysis of Genome-wide Association (GWA) data in Alzheimer's disease, in order to enable other researchers to examine particular variants or loci for their evidence of association. The files include p-values and direction of effect at over 7 million directly genotyped or imputed single nucleotide polymorphisms (SNPs). To prevent the possibility of identification of individuals from these summary results, allele frequency data are not released.

Data file description
Two dataset are provided. The first one corresponds to the meta-analysis results obtained in stage 1 including genotyped and imputed data (7,055,881 single nucleotide polymorphisms, 1000G phase 1 alpha imputation, Build 37, Assembly Hg19) of 17,008 Alzheimer's disease cases and 37,154 controls. The second one corresponds to the meta-analysis results of the 11,632 SNPs that were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls with the combined stage1/stage2 P-values.

Each file consists of the following information for each SNP and its association to Alzheimer's disease based on meta-analysis in the publication mentioned below. Although the individual datasets examined excluded any SNPs with call rates <95%, IGAP meta-analysis only analyzed SNPs either genotyped or successfully imputed in at least 40% of the AD cases and 40 % of the control samples across all datasets.

Chromosome: Chromosome of the SNP (Build 37, Assembly Hg19)
Position: Position of the SNP (Build 37, Assembly Hg19)
MarkerName: SNP rsID or chromosome:position if rsID not available
Effect_allele: Reference allele (coded allele)
Non_Effect_allele: Non reference allele (non coded allele)
Beta: Overall estimated effect size for the effect allele
SE: Overall standard error for effect size estimate
Pvalue: Meta-analysis Pvalue using regression coefficients (beta and standard error)

Description lifted from the archived IGAP website on 04/15/22. 

Molecular Data Type


Submission date: 

Stage 1:

Cases- 17,008
Controls- 37,154

Stage 2:

Cases- 8,572
Controls- 11,312


Stage 1: 7,055,881

Stage 2: 11,632

PI Information