Spectra of BRCA1 and BRCA2 mutations in Korean patients with breast cancer: the importance of whole-gene sequencing.

Jang JH, Lee JE, Kwon MJ, Ki CS, Kim JW, Nam SJ, Yang JH.

Source

Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Abstract

The frequencies and spectra of germline mutations in the BRCA1 and BRCA2 genes vary among populations. In the present study, the mutation spectra of the BRCA1/BRCA2 genes in Korean breast cancer patients were investigated using whole-gene sequencing method. A total of 134 unrelated Korean breast cancer patients who were identified as being at high risk of carrying BRCA1/BRCA2 mutations were included. PCR amplification and direct sequencing were performed covering all exons and flanking intronic sequences of the BRCA1/BRCA2 genes. A total of 26 mutations were detected in 31 of 134 patients (23.1%). The mutation detection rate in the present study is higher than those of previous studies using screening methods (2.5-11.3%) and similar to that of a recent study, which used whole-gene sequencing (21.2%). The BRCA2: c.7480C>T mutation, which has been suggested to be a founder mutation in Koreans, was detected in only one patient. Five mutations were recurrent but observed in no more than two patients. Given that the mutation detection rates using whole-gene sequencing were much higher than for screening methods and that there were no consistent observations of founder mutations, whole-gene sequencing of both BRCA1 and BRCA2 genes should be the method of choice to identify mutations in high-risk Korean patients.Journal of Human Genetics advance online publication, 5 January 2012; doi:10.1038/jhg.2011.139.