Study On BRCA1 Mutation And Methylation In Sporadic Breast Cancer

It is showed that breast cancer is related to genetic factors by the study on epidemiology in 1970's. Hall found breast and ovarian cancer susceptibility gene BRCA1 in 1990, and in 1994 it was coloned by Miki. BRCA1 gene Mutation is thought to account for approximately 45% of families with significantly high breast cancer incidence, and at least 80% of families with increased incidence of both early-onset breast cancer and ovarian cancer. Study 34 Chinese sporadic breast cancer cases on BRCA1 mutation by PCR-SSCP and DNA sequencing, find 2/34 cases existing base displace (G in place of A) in site 2430 of exonll. It indicates 185delAG and 5382insC are not the high mutation spots, so to screen them is meaningless; the low frequency (6%) of BRCA1 mutation is probably related to breast cancer, and screen it is also meaningless. Study by MSREs-PCR finds 6/34 cases (20%) existing abnormal methylation. Screen the abnormal methylation of BRCA1 has important clinical roles in estimating the danger of cancer, early diagnosis and therapy.