After reviewing the results from the primary genome-wide association analysis, top-ranking SNPs were annotated for function (i.e., synonymous, non-synonymous, splice-site, intronic, etc.) and aligned against the human genome assembly build 36.3 using the program WGAViewer ver. 1.25 [Ge and Goldstein, 2007]. Forty-two SNPs were chosen from the GWAS results and successfully genotyped in the family-based sample (see supplementary online material). Of these, 30 were selected from the top 250 ranking markers located within or near (<50 kb) genes of interest based on genic function and expression patterns, including regions exhibiting high regulatory potential and interspecies conservation (e.g., ESPERR score) [Taylor et al., 2006]. These were supplemented by 12 other SNPs outside the top 250, but still nominally significant (P = 0.05), identified as potentially relevant to neuroelectrical activity and neuronal development [e.g., Neuritin 1 (NRN1), Neurexophilin 1 (NXPH1), and serotonin receptor genes (HTR2A and HTR7)]. Genotyping assays were designed for the Sequenom MassArray system (Sequenom, San Diego, CA) using MassArray Assay Design Software. Genotyping used iPLEX assays (Sequenom, San Diego, CA), with alleles discriminated by mass spectrometry. Assays were tested
