The seven SNPs located within a 132 kb region of CHRM2 were investigated for association with P300 group phenotype using logistic regression. Genetic Map Interpolator (GMI) software (Mukhopadhyay et al., 2010) was used to retrieve current physical map positions from Ensembl (Ensembl 65); these physical positions were then used to linearly interpolate genetic map positions based on the Rutgers Combined Linkage-Physical Map (Kong et al., 2004; Matise et al., 2007). Tests for Hardy-Weinberg equilibrium (HWE), linkage disequilibrium measures, and allele frequencies were computed in Haploview (Barrett et al., 2005). No SNP was found to exhibit significant Hardy-Weinberg departure. SNP associations were tested using logistic regression with robust estimates of variance calculated to account for family clustering of offspring.
