A novel de novo BRCA2 mutation of paternal origin identified in a Spanish woman with early onset bilateral breast cancer.

Germ line mutations in either of the two major breast cancer predisposition genes, BRCA1 and BRCA2, account for a significant proportion of hereditary breast/ovarian cancer. Identification of breast cancer patients carrying mutations in any of these genes is primarily based on a positive family history of breast/ovarian cancer or early onset of the disease. In the course of mutation screening of the BRCA1 and BRCA2 genes in a hospital based series of patients with risk factors for hereditary breast/ovarian cancer, we identified a novel germ line mutation in the BRCA2 gene (c.51dupA) in a patient with early onset bilateral breast cancer and no family history of the disease. None of her parents carried the mutation, and paternity was confirmed. Subsequent molecular analysis demonstrated that the mutation was a novel de novo germ line mutation located in the paternal allele of the BRCA2 gene.