为了探讨中国乳腺癌家族中BRCAl基因突变情况,我们收集了15个乳腺癌家系,共41个对象,其中23例为乳腺癌患者,采用聚合酶链反应-单链构像多态性分析(PCR-SSCP)、直接DNA测序法对BRCA1编码基因进行了全序列分析。结果发现在15个家系中有4例(3种)基因突变,突变比例为26.7％(4/15)。其中一例2228insC为插入突变,致编码子711处蛋白截短;另3例(2种)突变为1884A→T和3232 A→G,分别引起单个氨基酸改变。我们认为BRCA1为家族性乳腺癌的遗传基因;在BRCA1以外还存在其他的乳腺癌易感基因。 To investigate the BRCA1 gene mutation in Chinese breast cancer families, we collected 15 breast cancer pedigrees, 41 subjects in total, 23 of whom were breast cancer patients. Polymerase chain reaction-single strand conformation polymorphism (PCR) -SSCP). The full-length sequence analysis of BRCA1 gene was carried out by direct DNA sequencing. In 15 families, 4 (3) gene mutations were found, with a mutation rate of 26.7% (4/15). One of the 2228insC was an insertion mutation that resulted in protein truncation at codon 711; the other three (2 species) were mutated to 1884A → T and 3232 A → G, respectively, causing a single amino acid change. We consider BRCA1 to be a genetic marker of familial breast cancer; there are other breast cancer susceptibility genes other than BRCA1.