P53 gene mutations of familial breast cancer and early-onset breast cancer in part population of southern China

Abstract

To investigate the site and characteristic of p53 gene mutations in familial or early-onset breast cancer patients in part population of southern China. Methods: A total of 150 patients with familial and early-onset breast cancer in parts population of southern China were enrolled. Genomic DNA was isolated from each peripheral blood sample, and the entire coding sequence and exon and intron splicing region of p53 gene were amplificated by PCR in the 150 patients. The mutation analysis were detected by denaturing high performance liquid chromatography (DHPLC) and confirmed by DNA sequence analysis. Results: In the 150 patients with familial and early-onset breast cancer, 6 mutations including one novel pathogenic mutation 869_888 ins20 (insert mutation) and 5 previously reported pathogenic mutations (deletion mutation 643_660del18 and 4 missense mutation 91G>A, 215C>G, 537T>G, 743G>A) were identified in p53 gene encoding region in 9 patients of breast cancer. Moreover, one same sense mutation 141G>A in exon 4, one 16 bases deletion in intron 3, and 9 single nucleotide polymorphisms in p53 gene introns were also identified. The total mutation frequency of p53 gene in 150 patients with familial breast cancer and early-onset breast cancer from part population of southern China was 6.00%, and the mutation frequency of familial breast cancer and early-onset breast cancer was 6.81% and 6.25%, respectively. Conclusion: The total mutation frequency of p53 gene in 150 patients with familial breast cancer and early-onset breast cancer from partpopulation of southern China is higher than the frequency previously reported. The pathogenicity of the novel mutations (insert mutation) 869_888ins20 will be confirmed by function analysis in the future study. The deletion mutation 643_660del18 enriches the p53 gene mutation database among Chinese population, which is probably the specific mutation of breast cancer in Chinese population.