Samples were genotyped on the Illumina HumanOmni1-Quad v1.0 microarray, containing 988,306 autosomal SNPs, at the Center for Inherited Disease Research and the Yale Center for Genome Analysis. Genotypes were called using GenomeStudio software V2011.1 and genotyping module V1.8.4 (Illumina, San Diego, CA, USA). (See Gelernter et al., 2014 for a detailed description of genotyping and quality control measures.)