Genotyping was performed by the Center for Inherited Disease Research (CIDR). DNA was obtained from blood or lymphoblast cell lines. Genotyping was performed using the Illumina Infinium II assay protocol with hybridization to Illumina HumanHap 1M BeadChips (Illumina, San Diego, CA, USA). A subset of the data is available through dbGaP (http://www.ncbi.nlm.nih.gov/sites/entrez?db=gap; Accession number: phs000125.v1.p1). Twenty-seven samples were removed due to poor sample quality. Blind duplicate reproducibility was >99.9%. Samples with genotypes for at least 98.0% of the markers were considered for inclusion in analyses and were screened for cryptic relatedness, population stratification, etc., resulting in the removal of 13 additional samples. SNPs with a call rate of ≥98.0% in the EA sample were included in analyses. SNPs were excluded if the minor allele frequency was <1% in the combined case and control dataset; further SNPs were excluded if significant (p<10−4) deviation from Hardy Weinberg equilibrium were observed. Additional details are provided in Edenberg et al. (2010). The GWAS analysis was conducted in PLINK version 1.05, for all autosomes and the X chromosome, with age and sex included as covariates.
