OBJECTIVETo detect the mutations of BRCA1 and BRCA2 in sporadic breast cancer and study the relationship between BRCA1 and BRCA2 mutations and breast cancer.

METHODSBreast cancer tissues of 144 patients and breast tissues of 30 cases of healthy people who were treated from December 2000 to September 2005 were studied. DNA was extracted by the phenol-chloroform method. Fragments of exon 2, exon 3, exon 5, exon 6, exon 7, exon 8, exon 9, exon 10, exon 11, exon 12, exon 13, exon 14, exon 15, exon 16, exon 17, exon 18, exon 19, exon 20, exon 21, exon 22, exon 23 and exon 24 in the BRCA1 gene and exon 10 and exon 14 in the BRCA2 gene were amplified by polymerase chain reaction. Mutation screening was performed by single-strand conformation polymorphism analysis and alterations were confirmed by DNA sequencing.

RESULTSA total of 20 single nucleotide changes in BRCA1 were detected in the 144 cases of breast cancer patients. The total mutation rate was 13.9% and missense mutation rate was 11.1%. No mutation was detected in the BRCA2 and controls.

CONCLUSIONSMutations in BRCA1 may play an important role in evaluation of sick risk, earlier diagnosis and gene therapy of breast cancer in southern Chinese populations.