[Large deletion in mismatch repair genes uncovered by quantitative multiplex PCR-high performance liquid chromatography system].

Objective: Establishing a new method on the basis of multiplex PCR-high performance liquid chromatography (HPLC) for screening a large deletion in mismatch repair genes.

Methods: Thirty-five pairs of primers were used to amplify all 16 exons of MSH2 and all 19 exons of MLH1 gene in 8 multiplex PCR. The products of multiplex PCR were analysed for the large deletion with Double Strand DNA Analysis System of HPLC. Firstly, validation of the method was tested on positive and negative controls in blind analysis. Secondly, 14 blood cell DNA samples from hereditary nonpolyposis colorectal cancer (HNPCC) patients and 13 colorectal cancer (CRC) tissues DNA samples from sporadic CRC patients were checked with the new developed method.

Results: (1) the genomic deletions in all 4 of positive controls were identically uncovered with the new method; (2) a novel germline and a novel somatic large deletions were unveiled in 1/14 HNPCC patients and in 1/13 CRC tissues.

Conclusion: The method developed on multiplex PCR-HPLC is reliable for uncovering large genomic deletion in mismatch repair genes, and can be taken as a valuable addition to mutation screening system.