A Study for Germline Mutation of BRCA1 in Early Onset Breast Cancer Patients

Kim, Hyo Joon; Lee, Ji Yeon; Lee, Eun Sook; Koo, Bum Hwan

Abstract

The cumulative incidence of breast cancer in Korea is low, being about one-fifth of that in the United States. This low incidence has been mainly explained by environmental factors, and recently, however, racial variations in the disease-causing genes should also be considered. The BRCA1 is one of the common genes involved in early-onset breast cancer and/or ovarian cancer in the United States and Northern Europe. However, the involvement of BRCA1 in Korean'breast cancer patients are still unclear. We performed germline mutation screening of the BRCA1 gene by DNA single strand conformation polymorphism (SSCP) analysis. We examined 27 breast cancer patients who were diagnosed less than 35 years by age including two cases with family history of breast cancer. Our study showed no germline mutation at the exons 2, 11 and 20, which were known as the supreme susceptible regions of BRCA1 mutations. Even though our cases did not fulfilled the criteria of familial breast/ovarian cancer, the proprotion of families who inherit the mutated BRCA1 allele seems to be very small and might be negligible among Korean population. Therefore, it is considered that the BRCA1 itself cannot be a major susceptibility gene and the contributions of other genes might be important for the breast cancer.