[Sequence analysis of BRCA1 gene in young breast cancer patients and/or positive family history].

We analyzed the complete coding region with adjacent intron sequences of the BRCA1 gene in eight patients with hereditary and/or early-onset breast/ovarian cancer. We detected one germline mutation in exon 5 in a 35-year-old woman with early-onset breast and ovarian cancer and 10 polymorphisms, of which one has not been published so far. To determine whether certain BRCA1 polymorphisms are associated with an increased risk for breast cancer, we will compare genotype distributions of early-onset breast cancer populations with matched controls.