To achieve our goal, the GABRA2 SNP rs279871 was selected following the rationale detailed in the introduction. Of the 820 subjects in the prior study (Kuperman et al., 2013), 691 had been genotyped for this SNP on chromosome 4 using the Sequenom MassArray (Sequenom, San Diego, CA, USA). Plink (Purcell et al., 2007) was used to confirm family structure, while PEDCHECK (O'Connell & Weeks, 1998) was used to correct for Mendelian inconsistencies.
