source: Shiraz E Medical Journal

year: 2014

authors: Tayebeh Hamzehloei, Mahdieh Davoodnejad Dehsorkhi

Colorectal cancer (CRC) is the second most prevalent cancer worldwide, and in 35% of cases it is an inherited form. The most common inherited forms of CRC include; Lynch syndrome, familial adenomatous polyposis (FAP), attenuated FAP, and MUTYH-associated polyposis (MAP). Although they are inherited, they have different phenotypic effects with regards to the number of polyposis, age of onset and the pattern of inheritance. Some of these CRCs are associated with other extracolonic manifestation symptoms. MUTYH-associated polyposis (MAP) was first described in 2002. MUTYH is a component of a base excision repair system that protects the genomic information from oxidative damage. When the MUTYH gene product is impaired by bi-allelic germline mutation, it leads to the mutation of cancer-related genes, such as the APC and/or the KRAS genes, via G to T transversion. MAP is a hereditary colorectal cancer syndrome inherited in an autosomal-recessive fashion. The proposed mechanism of individual CRC is distinguished in this review paper.