[Mutation screening of MLH1 and MSH2 genes in two Chinese families with hereditary nonpolyposis colorectal cancer].
OBJECTIVE
To identify the MLH1 and MSH2 gene mutation in two hereditary nonpolyposis colorectal cancer (HNPCC) families.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Xie
Zhi-guo
ZG
National Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, 410078 P. R. China.
Hu
Zheng-mao
ZM
Gong
Hui-yong
HY
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D044466:Asian People; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein / Q000235:genetics*; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length
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