ABSTRACT
<p><b>OBJECTIVE</b>To gain an insight into the large intragenic hMSH2 and hMLH1 deletions in Chinese hereditary nonpolyposis colorectal cancer (HNPCC) families.</p><p><b>METHOD</b>The large intragenic hMSH2 and hMLH1 deletions in 17 probands of HNPCC families were detected with multiplex ligation-dependent probe Three large intragenic hMSH2 deletions of examplification (MLPA) and GeneMapper techniques.</p><p><b>RESULTS</b>on 8, exon 1-6, and exon 1-7 were found in three families respectively, and no hMLH1 deletion was found. The deletions accounted for 19% of the total hMSH2 and hMLHI germline pathogenic mutations.</p><p><b>CONCLUSIONS</b>The incidence of large intragenic mismatch repair (MMR) genes deletions is relatively higher in Chinese families, and hMSH2 deletions may be more common. It is necessary to detect the large intragenic MMR genes deletions in the molecular detection of HNPCC.</p>