Frequency of the CHEK2 1100delC Mutation in Korean Women with Early Onset Breast Cancer

Abstract

2 (CHEK2 1100delC) are associated with an increased risk for breast cancer in women carrying this mutation. It is a lowpenetrance breast cancer susceptibility allele, frequently observed in patients with a family history of breast cancer and/or young age, with the frequency varying according to race or ethnicity. In this study, we evaluated the significance of CHEK2 1100delC in predisposition to breast cancer by assessing its frequency in material from 101 Korean women patients with early-onset breast cancer. Methods: One hundred and one Korean patients with earlyonset breast cancer (40 yr old or younger) were selected for this study. All the patients had been screened for BRCA1 and BRCA2 mutations and 14 patients had deleterious mutations. Of the 101 patients entered for this study, 14 had family history of breast cancer and 7 had bilateral breast cancers. Mutation detection of CHEK2 1100delC was based on analysis of primer extension products generated from previously-amplified genomic DNA using a chip based MALDI-TOP mass spectrometry platform (Sequenom, Inc., San Diego, CA, USA). Results: None of the 101 Korean patients with a family history of breast cancer and early-onset breast cancer who were candidates for the BRCA1 and BRCA2 test carried the 1100 delC mutation, which is observed in Caucasians with limited frequency. Conclusion: We previously observed higher or comparable prevalence of BRCA1 and BRCA2 mutations in Korean patients with breast cancer compared to Caucasians. However, the CHEK2 1100delC mutation is absent or infrequent in Korean patients with breast cancer who have a high risk of BRCA1 and BRCA2 mutations, making its screening irrelevant.