Detection of hMSH2 and hMLH1 mutations in Chinese hereditary non-polyposis colorectal cancer kindreds.
OBJECTIVE
To establish and validate the mutation testing for identification and characterization of hereditary non-polyposis colorectal cancer (HNPCC) in suspected Chinese patients.


METHODS
Five independent Chinese kindreds with HNPCC fulfilling the classical Amsterdam criteria were collected. Genomic DNA was extracted after informed consent was obtained. The coding region of hMSH2 and hMLH1 genes was detected by polymerase chain reaction (PCR) and denaturing high-performance liquid chromatography (DHPLC). Mutations identified in the proband by DHPLC were directly sequenced using a 377 DNA sequencer, analyzed with a basic local alignment tool (BLAST), and tested in the corresponding family members by direct DNA sequencing.


RESULTS
Mutations were identified in two Chinese HNPCC kindreds. One was the missense mutation of hMSH2 c.1808A-->G resulting in Asp 603 Gly identified in the proband of the fifth HNPCC (HNPCC5) kindred. In the HNP5 kindred, three family members were found to have this mutation and two of them had colorectal cancer. The other mutation of hMLH1 c.1882A-->G was identified in the HNP2 kindred's proband, which might be the nonsense mutation analyzed by BLAST.


CONCLUSIONS
Pedigree investigation and mutation testing of hMSH2 and hMLH1 are the practical methods to identify high-risk HNPCC patients in China.
Zhang
Chang-Hua
CH
Department of Gastrointestinopancreatic Surgery of the First Affiliated Hospital, Gastric Cancer Center, Sun Yat-Sen University, Guangzhou 510080, Guangdong Province, China.
He
Yu-Long
YL
Wang
Fang-Jin
FJ
Song
Wu
W
Yuan
Xi-Yu
XY
Yang
Dong-Jie
DJ
Chen
Chuang-Qi
CQ
Cai
Shi-Rong
SR
Zhan
Wen-Hua
WH
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics; D001483:Base Sequence; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000208:ethnology; D005820:Genetic Testing / Q000379:methods* / Q000592:standards*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D012307:Risk Factors
D048868:Adaptor Proteins, Signal Transducing; C501486:MLH1 protein, human; D009687:Nuclear Proteins; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein