Investigation of APC mutations in a Turkish familial adenomatous polyposis family by heterodublex analysis

Familial adenomatous polyposis is an autosomal dominant disease characterized by the presence of 100 or more colorectal adenomatous polyps. Mutations in the adenomatous polyposis coli gene are primarily responsible for the development of this disease. This study was designed to investigation of adenomatous polyposis coli (APC) gene mutations in members of familial adenomatous polyposis family to identify individuals at risk of the disease. We examined one patient with familial adenomatous polyposis and 21 family members including one affected person from familial adenomatous polyposis and 20 nonsymptomatic persons. We studied E, D, F, and G segments of exon 15 of the adenomatous polyposis coli gene by heteroduplex analysis. We used silver staining method for staining. We found a mutation for five persons at segment F of exon 15 of the adenomatous polyposis coli gene. Two of them were affected by colorectal cancer, one of whom was the proband, and the other three were nonsymptomatic family members. The pathogenetic mutation was a T deletion at codon 1172, causing a frameshift in the adenomatous polyposis coli gene, as a result of the sequencing analysis of these cases. Investigation of adenomatous polyposis coli gene mutations is very important for the identification of genetic susceptibility to colorectal cancer and for the definition of tumor developing at an early stage. Furthermore, the identification of this mutation for the first time in a Turkish family will be useful to foster further studies on familial adenomatous polyposis in Turkey.