OBJECTIVETo investigate the prevalence of BRCA1 and BRCA2 gene mutations among breast cancer patients with affected relatives in Shanghai of China.

METHODSThirty-five breast cancer patients who had at least one first-degree relative affected were analyzed, among whom 13 patients suffered from breast cancer at age of less than 40 years. A comprehensive BRCA1 and BRCA2 mutation analysis was performed through denaturing high-performance liquid chromatography (DHPLC) and subsequent DNA direct sequencing.

RESULTSFour mutations in BRCA1 gene, including 2 novel splice-site mutations (IVS17-1G>T, IVS21+1G>C) and 2 frameshift mutations (1100delAT; 5640delA) were identified. One frameshift mutation (5802delAATT) was detected in exon 11 of BRCA2. Additional 12 novel single nucleotide polymorphisms(SNPs) were detected, including a novel unclassified variant and 7 novel intronic variants in BRCA1, and 4 novel intronic variants in BRCA2, with which all caused no alteration of amino acid coding. The mutation frequency of BRCA1 and BRCA2 in patients with family history was 11.4% and 2.9%, respectively.

CONCLUSIONTwo novel mutations in BRCA1 may be mutations characterized to familial breast cancer of Chinese Shanghai population. The BRCA2 may contribute to mutation less than BRCA1 in familial breast cancer. Our data contribute to information on mutation spectrum of BRCA gene in Chinese population and also offer a recommended screening mode for clinical genetic testing policy in China.