A large multisite cancer family is linked to BRCA2.

We identified a large French-Canadian family with 21 cases of breast cancer, including two affected brothers. Segregation of markers from chromosome 13q in this family showed linkage to the BRCA2 gene locus (lod = 3.67 at D13S289). A number of cancers of other types occurred in this family, including three cases of prostate cancer and two cases of lymphoma. The penetrance of breast cancer among BRCA2 carriers is estimated to be 75% to the age of 70.