['A mutation in the androgen receptor (AR) gene, namely AR R726L, was described in 2% of Finnish men with sporadic or familial prostate cancer and was associated with an approximately sixfold increased risk of prostate cancer. We set out to determine the incidence of this mutation in a sample of men with either early-onset and/or familial prostate cancer in the United States.', 'Five hundred forty-eight men with prostate cancer from 411 unrelated families participating in the University of Michigan Prostate Cancer Genetics Project (PCGP) were studied. Allele-specific oligonucleotide hybridization was used to detect the presence of the AR R726L mutation in germline DNA.', "None of the 548 prostate cancer patients studied, including 513 White, 29 African American, 3 Asian, and 3 Hispanic men, were found to carry the AR R726L allele. Therefore, the prevalence of this allele is significantly less than that observed among Finnish men with prostate cancer (Fisher's exact test, P = 0.002)."] Is r726L androgen receptor mutation uncommon in prostate cancer families in the united states?