Rapid detection of regionally clustered germ-line BRCA1 mutations by multiplex heteroduplex analysis

Germ-line mutations of the BRCA1 gene are responsible for a substantial proportion of families with multiple cases of early-onset breast and/or ovarian cancer. Since the isolation of BRCA1 last year, >65 distinct mutations scattered throughout the coding region have been detected, making analysis of the gene time consuming and technically challenging. We have developed a multiplex heteroduplex analysis that is designed to analyze one- quarter of the coding sequence in a single-step screening procedure and that will detect ~50% of all BRCA1 mutations so far reported in breast/ovarian cancer families. We have used this technique to analyze BRCA1 in 162 families with a history of breast and/or ovarian cancer and identified 12 distinct mutations in 35 families.