Searching for new breast cancer-associated genes. ABRAXAS1 gene mutations in the group of BRCA1-negative patients.

In the present study, we analysed the association of mutations of a BRCA1-associated gene, ABRAXAS1, with the risk of development of breast cancer (BC) in BRCA1-negative women from North-Central Poland. A hundred women with consecutively diagnosed BC and 100 women belonging to the control group were screened for new mutations predisposing to breast cancer. The first step was a test carried out in order to find one of the three Polish founder mutations in the BRCA1 gene. In 96 BRCA1-negative patients two missense variants: c.422C>T and c.1042G>A as well as two intronic variants: IVS3-34G>A, IVS3-44T>C were detected in the ABRAXAS1 gene. The c.422C>T mutation was detected in one of 96 women diagnosed with breast cancer (1.04%); it was not associated with increased risk of disease in this group, compared to the controls (p = 0.49), but the odds ratio was 3.314; 95% CI: 0.122-75.352. IVS3-44T>C was found more frequently in the control group (15/93) than in the tested group (1/85), OR 0.062; 95% CI: 0.008-0.480, p = 0.007, which may suggest protective properties of this variant against tumorigenicity. The data obtained from the present study suggest the necessity for further research to be conducted on the ABRAXAS1 gene in relation to hereditary predisposition to breast cancer.