No evidence for a role of BRCA1 or BRCA2 mutations in Ashkenazi Jewish families with hereditary prostate cancer.

BACKGROUND

Two genes responsible for hereditary breast cancer (BRCA1 and BRCA2) have been identified, and predisposing mutations identified. Several studies have provided evidence that germline mutations in BRCA1 and BRCA2 confer an increased risk of prostate cancer. Based on these findings, one might expect to find an increased frequency of mutations in these genes in family clusters of prostate cancer. The Ashkenazi Jewish population is unique in that it has an approximate 2% incidence of specific founder BRCA1 and BRCA2 mutations (i.e., 185delAG and 5382insC in BRCA1, and 6174delT in BRCA2).

METHODS

To address the question of whether or not mutations in either of these genes were overrepresented in prostate cancer families, we searched for these mutations in germline DNA samples collected from affected and unaffected members of 18 Ashkenazi Jewish families, each having at least 3 first-degree relatives affected with prostate cancer.

RESULTS

No mutations were found in the BRCA1 gene in any of the 47 individuals tested. One individual possessed a BRCA2 mutation (6174delT). This individual was unaffected at the time of analysis, but had an affected paternal uncle, and an affected first cousin, neither of whom harbored the mutant gene.

CONCLUSIONS

In this sample of Ashkenazi prostate cancer families, the frequency of founder BRCA1 and BRCA2 mutations was not elevated, suggesting that such mutations will account for only a small, perhaps minimal, fraction of familial prostate cancer.