MUTYH the base excision repair gene family member associated with colorectal cancer polyposis

Colorectal cancer is classified in to three forms: sporadic (70–75%), familial (20–25%) and hereditary (5–10%). hereditary colorectal cancer syndromes classified into two different subtypes: polyposis and non polyposis. Familial Adenomatous polyposis (FAP; OMIM #175100) is the most common polyposis syndrome, account for <1% of colorectal cancer incidence and characterized by germline mutations in the Adenomatous polyposis coli (APC, 5q21- q22; OMIM #175100). FAP is a dominant cancer predisposing syndrome which 20–25% cases are de novo. There is also another polyposis syndrome; MUTYH associated polyposis (MAP, OMIM 608456) which it is caused by mutation in human Mut Y homologue MUTYH (MUTYH; OMIM 604933) and it is associated with multiple (15–100) colonic adenomas. In this paper we discuss MUTYH mechanism as an important member of Base Excision Repair (BER) family and its important role in polyposis condition.