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 on two independent groups, 40 unrelated European-American individuals and 40 unrelated African-American individuals (samples obtained from Coriell Cell Repositories). SNPs that were not in Hardy Weinberg equilibrium in both groups were not genotyped in the COGA families. All SNPs were tested for Mendelian inheritance using the program PEDCHECK [O’Connell and Weeks, 1998]. Marker allele frequencies were computed using the program USERM13 [Lange et al., 1988].
