Mutation screening of MLH1 and MSH2 genes in two Chinese families with hereditary nonpolyposis colorectal cancer / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the MLH1 and MSH2 gene mutation in two hereditary nonpolyposis colorectal cancer (HNPCC) families.</p><p><b>METHODS</b>Polymerase chain reaction and DNA sequencing were used to screen for MLH1 and MSH2 gene mutation, and PCR-restriction fragment length polymorphism and DNA sequencing were performed to confirm the mutation.</p><p><b>RESULTS</b>By DNA sequencing, a novel mutation of c.243_244insA located at the exon 3 of MLH1 gene was detected in family A, while c.1215_1218dupCCGA mutation located at the exon 7 of MSH2 gene was detected in family B. These two mutations can cause the formation of premature proteins.</p><p><b>CONCLUSION</b>The novel mutations c.243_244insA in MLH1 gene and c.1215_1218dupCCGA in MSH2 gene were the disease-causing mutations in the two HNPCC families.</p>