Specifically the overwhelming majority of hereditary nonpolyposis colorectal cancers (HNPCC) are attributed to mutations in the genes encoding the MutS and MutL homologues MSH2 and MLH1 respectively, which allows them to be classified as tumour suppressor genes.
Disruption of an exon splicing ehancer in exon 3 of MLH1 gene is the cause of HNPCC (hereditary non polyposis colorectal cancer) in a Quebec family.
Under the name constitutional mismatch repair-deficiency, (CMMR-D), it has been mapped to MLH1, MSH2, MSH6 or PMS2.
The most frequent mutations in HNPCC are mutations in the MSH2 and MLH1 genes.
MLH1 |