The gene for hereditary breast-ovarian cancer, BRCA1, maps distal to EDH17B2 in chromosome region 17q12–q21

Abstract

A gene for hereditary breast and ovarian cancer, BRCA1, has been mapped to chromosome 17q12–q21. This gene is responsible for cancer susceptibility in the majority of families with multiple cases of ovarian cancer and early-onset breast cancer. We report linkage results of a family with 10 cases of breast cancer and a single case of ovarian cancer. A recombinant event in this family places BRCA1 distal (telomeric) to the locus EDH17B2, which codes for the enzyme estradiol 17β-dehydrogenase II. This recombinant is based on the appearance of breast cancer in a 45 year old woman. Under our genetic model, we estimate the probability that this woman carries a BRCA1 mutation to be 94%. These data further reduce the region of assignment of BRCA1 on chromosome 17q12–q21 and should expedite positional cloning of this important gene.