adjusting for age, sex, and 10 PCs we were able to more directly compare independent associations between the candidate phenotypes and the established AHD1B variants relevant to each ancestry in a standardized manner. We used different SNPs for EAs and AAs because populations often differ in the frequency of alleles at polymorphic sites and a polymorphism in a gene in one population may not be present or may be very uncommon in another population. Two different single nucleotide polymorphisms in ADH1B are present in EAs and AAs and both are associated with alcohol dependence in the respective populations. However, the prevalence of the minor allele of each is too low in the opposite population (e.g., in AAs, rs1229984 has a minor allele frequency that is nearly zero) for analyses in the opposite populations to be meaningful. Ordered logit regression was modeled using the SAS 9.2 procedure, GENMOD.
