LOCALIZATION OF A BREAST-CANCER SUSCEPTIBILITY GENE, BRCA2, TO CHROMOSOME 13Q12-13

A small proportion oi breast cancer, in particular those cases arising at a young age, is due to the inheritance of dominant susceptibility genes conferring a high risk of the disease. A genomic linkage search was performed with 15 high-risk breast cancer families that were unlin ked to the BRCA1 locus on chromosome 17q21. This analysis localized a second breast cancer susceptibility locus, BRCA2, to a 6-centimorgan i nterval on chromosome 13q12-13. Preliminary evidence suggests that BRC A2 confers a high risk of breast cancer but, unlike BRCA1, does not co nfer a substantially elevated risk of ovarian cancer.