Differences in ornithine decarboxylase and androgen receptor allele frequencies among ethnic groups.

Recent evidence suggests that the A allele of the ornithine decarboxylase (ODC) gene is a genetic risk factor for prostate cancer. ODC is a target gene of the highly polymorphic androgen receptor (AR) gene, short alleles of which have been associated in some studies with increased prostate cancer risk. We determined ODC allele frequencies and distribution of AR alleles in American Caucasians, African-Americans, Hispanics, Europeans, and Africans. The frequency of the ODC A allele varied from 0.183 (Hispanics, Europeans) to 0.415 (Africans) with American Caucasian and African-Americans having intermediate values. The mean number of CAG repeats in the AR gene varied from 19.8 (African-Americans) to 25.1 (Hispanics). It is possible that ethnic differences in risk alleles for ODC and AR may account for some of the ethnic variation in prostate cancer risk.