Genetic variation of 3β-hydroxysteroid dehydrogenase type II in three racial/ethnic groups: Implications for prostate cancer risk

Abstract

BACKGROUND. Elevated prostatic dihydrotestosterone (DHT) has been suggested to increase the risk of prostate cancer. The HSD3B2 gene encodes the type II 3β-hydroxysteroid dehydrogenase: one of two enzymes that initiate the inactivation of DHT. Thus, the HSDSB2 gene is a candidate gene for predisposition to prostate cancer. METHODS. We have determined the distribution of a complex dinucleotide repeat in the HSD3B2 gene in high- risk African-Americans, intermediate-risk Euro-Americans, and lowrisk Asians. Genomic DNA from 312 individuals was amplified by polymerase chain reaction (PCR) and analyzed by electrophoresis on denaturing polyacrylamide gels. RESULTS. We have found that certain alleles are either unique to or much more common in either African-Americans, Asians, or Euro-Americans. Our data also substantially expand the number of alleles reported for the complex dinucleotide repeat polymorphism in the HSD3B2 gene. CONCLUSIONS. Our report demonstrates substantial genetic variation in the HSD3B2 gene. We hypothesize that allelic variants of the HSD3B2 gene may play a role in predisposition to prostate cancer, and in explaining the substantial racial/ethnic variation in risk.