Genotyping assays were designed for the Sequenom MassArray system (Sequenom, San Diego, CA) using MassArray Assay Design Software. Genotyping used iPLEX Gold assays (Sequenom, San Diego, CA), with alleles discriminated by mass spectrometry. Assays were tested on two independent groups, 40 unrelated EA individuals and 40 unrelated African-American (AA) individuals 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).
