P53Gene Mutations Of Familial Bfeast Cancer And Early-onset Breast Cancer In Parts Of Southern China

Background:Germ-line mutations of the tumor suppressor gene, P53, can increase the risk of breast cancer,but the reports about pathogenic mutation of P53gene were rare.Additionally the prevalence of P53gene mutation among high risk of breast cancer patients with genetic background in parts of Southern China is still indeterminate.Objectives:The purpose of this study was to investigate the prevalence and speciality of P53gene mutations among familial or early-onset breast cancer patients in parts of Southern China, further more to discuss the significance of the mutations.Method:150familial and early-onset breast cancer patients in parts of Southern China are enrolled. In total,88cases（58.66%） in the study are familial, among them18cases are both familial and early-onset,62cases are early-onset without family history.Genomic DNA was isolated from each peripheral blood sample, and all the150cases had been detected for the entire coding sequence and splicing sites of P53gene by using PCR.The mutation analysis were detected by using DHPLC and DNA sequence analysis.Result:Six mutations including one novel pathogenic mutation（insert mutation）869₈88ins20and5previously reported pathogenic mutations （deletion mutation643₆60del18and4missense mutation91G>A,215C>G,537T>G,743G>A）were identified in P53gene encoding region among9cases of breast cancer patients.Moreover one samesense mutation141G>A in exon4,one16bases deletion in intron3and9single nucleotide polymorphisms in P53gene introns were also identified.The total mutation frequency of P53gene in150familial breast cancer and early-onset breast cancer patients from parts of Southern China is6.00%.The mutation frequency of familial breast cancer and early-onset breast cancer patients respectively are6.81%and6.25%.Conclusion:The total mutation frequency of P53gene in familial breast cancer patients in parts of Southern China is higher than the data of previous literature reported at home and abroad, and probablely it is the charecteristic of P53mutation of familial and early-onset breast cancer patients among this region. P53mutation may be crucial in early-onset breast cancer in parts of Southern China, so it is worthy of further research and analysis.The pathogenic significance of the novel mutations（insert mutation）869₈88ins20will be confirmed by function alalysis in the future.The deletion mutation643₆60del18enriches the P53gene mutation database among chinese population,and probably is the specific mutation of breast cancer in chinese population.