Progression to colonic carcinoma has been associated with
a) mutations of MSH2, MSH6, and MLH1
b) mutation of DPC4 gene
c) Mutation of p21 gene
d) Mutation of Rb gene
e) Mutation of p53 gene
Answer:
a) mutations of MSH2, MSH6, and MLH1
Explanation
Colon cancer is one of the most common inherited cancer syndromes known. Among the genes found to be involved in colorectal cancer are: MSH2 and MSH6 both on chromosome 2 and MLH1, on chromosome 3. Normally, the protein products of these genes help to repair mistakes made in DNA replication. If the MSH2, MSH6, and MLH1 proteins are mutated and therefore don't work properly, the replication mistakes are not repaired, leading to damaged DNA and, in this case, colon cancer