BRCA1 4153delA founder mutation in Russian ovarian cancer patients.

The BRCA1 4153delA allele is frequently referred to as the Russian founder mutation, as it was initially detected in several cancer families from Moscow. Our earlier studies have demonstrated 1% occurrence of BRCA1 4153delA heterozygosity in familial and/or early-onset and/or bilateral Russian breast cancer (BC) patients. Since literature data suggest that the 4153delA variant is more associated with ovarian cancer (OC) than with BC, we expected to reveal a highly elevated frequency of this genotype in Russian ovarian cancer series. However, real-time allele-specific PCR genotyping has detected only two BRCA1 4153delA carriers out of 177 unselected OC patients (1.1%). Both these carriers were early-onset and had serous carcinomas of grade 3. Thus, our study supports neither the Russian origin of BRCA1 4153delA mutation, nor its selectivity towards ovarian versus breast cancer predisposition.