Hereditary nonpolyposis colorectal cancer
What is Hereditary nonpolyposis colorectal cancer?
An autosomal dominant predisposition to early-onset colorectal cancer in the absence of adenomatosis. The disease phenotype may be limited to the colorectum (Lynch syndrome I) or coexist with extracolonic tumors such as endometrial or gastric cancer among others (Lynch syndrome II). The genetic basis is in one of several genes responsible for DNA mismatch repair; in over 90% of cases, the mutation is one of two genes: MSH2 and MLH1.