Genotyping was performed using Illumina’s GoldenGate assays (Illumina, San Diego, CA, USA) at the Genome Technology Access Center at Washington University School of Medicine in St. Louis. Five CHRM2 SNPs, rs978437, rs7800170, rs1824024, rs2061174, and rs2350786, were used in the analysis. The first three are upstream of Exon 4, the other two downstream. All of the SNPs were in Hardy-Weinberg equilibrium. The pairwise r2 of the SNPs ranged from 0.778 to 0.141.
