[Mutation detection of mismatch repair genes in hereditary nonpolyposis colorectal cancer by denaturing high-performance liquid chromatography].
OBJECTIVE
To establish DHPLC method in detecting mutations of mismatch repair genes, hMLH1 and hMSH2, and to identify germline mutations of hMLH1 and hMSH2 in HNPCC kindreds fulfilling Chinese HNPCC criteria.


METHODS
Fourteen peripheral blood DNA samples from 14 unrelated HNPCC probands fulfilling Chinese HNPCC criteria were obtained respectively. PCR amplified 35 exons of two main mismatch repair genes, hMLH1 and hMSH2. DHPLC followed by DNA sequencing was used to detect and confirm mutations.


RESULTS
a total of 41 colorectal cancers and 19 extracolonic tumors were developed in 14 HNPCC kindreds, and gastric cancer was the most common extracolonic tumor type. Twelve single nucleotide changes were identified by DHPLC in 14 probands. Among them, three were missense mutations, one was a nonsense mutation. Other single nucleotide changes included five single nucleotide polymorphisms, two intron single nucleotide changes, one synonymous mutation. hMLH1 EXON19 CODON749 TAC-->TAG (Tyr-->X), hMSH2 EXON12 CODON629 CAA-->CGA (Gln-->Arg) and hMSH2 EXON15 CODON839 CAT-->CGT (His-->Arg) were new discovered mutations.


CONCLUSIONS
(1) DHPLC was considered to be highly effective, convenient technique with consistent results for the mutation detection of hMLH1 and hMSH2 genes. (2) Valid mutations of hMLH1 and hMSH2 genes were identified in about one-third HNPCC kindreds fulfilling Chinese HNPCC criteria and missense mutation was the most common mutational types in this cohort of families.
Huang
Yan-qin
YQ
Cancer Institute, 2nd Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China.
Yuan
Ying
Y
Wang
Ya-ping
YP
Zhu
Ming
M
Zhang
Su-zhan
SZ
Zheng
Shu
S
D048868:Adaptor Proteins, Signal Transducing; D044466:Asian People / Q000235:genetics*; D020137:Base Pair Mismatch; D002352:Carrier Proteins / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D018389:Codon, Nonsense; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D005820:Genetic Testing; D018095:Germ-Line Mutation; D006801:Humans; D008297:Male; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D018389:Codon, Nonsense; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein