BRCA2 GERMLINE MUTATIONS IN SWEDISH BREAST-CANCER FAMILIES

Mutations in the breast cancer susceptibility gene (BRCA2) are believe d to be responsible for a significant fraction of hereditary breast ca ncer. To determine the BRCA2 mutation spectrum in a subset of Swedish breast cancer families, 162 families were screened for germline mutati ons in this gene. A combination of RT-PCR, PTT and direct DNA sequenci ng was used. Two mutations and one previously reported polymorphic var iant resulting in a truncated protein were identified. Our data sugges t that only a small proportion of Swedish breast cancer families is at tributable to BRCA2 germline mutations. This result, in combination wi th the low frequency of BRCA1 germline mutations identified in our pre vious study, suggests additional high penetrant as well as low penetra nt breast cancer susceptibility genes are involved in familial breast cancer.