Prevalence of mutations in APC, CTNNB1, and BRAF in Tunisian patients with sporadic colorectal cancer.

Sporadic colorectal tumorigenesis is caused by alterations in the Wnt (APC, CTNNB1) and Ras pathways. Our objective was to analyze the occurrence of these genetic alterations in relation to tumor and patient characteristics. The prevalence of somatic alteration in the hot-spot regions of the APC, BRAF, and CTNNB1 genes was investigated in 48 unselected and unrelated Tunisian patients with sporadic colorectal cancer, and the association between the molecular features at these genes in relation to tumor and patient characteristics (age at diagnosis, sex, tumor localization, stage, and differentiation) was analyzed.

First genetic analysis in Tunisian familial adenomatous polyposis probands.

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease characterized by the development of hundreds to thousands of adenomatous polyps in colon and rectum. The APC gene (adenomatous polyposis coli) is considered as the major mutated gene in FAP. It has been shown that biallelic germline mutations in the base-excision-repair gene MYH can be responsible for a recessive inheritance of adenomatous polyposis (AP).

Do we know all there is to know about Familial Adenomatous Polyposis?

Familial Adenomatous Polyposis (FAP) and Attenuated FAP (AFAP) are caused by a germline mutation in the Adenomatous polyposis coli (APC) gene. Recently, a new pathway characterized by a biallelic mutation in the MYH gene, with a recessive model of inheritance was discovered for this inherited syndrome. This report describes a Tunisian patient with an attenuated FAP phenotype, presenting seven colon polyps and an adenocarcinoma but no detectable germline mutations in the FAP target genes.

Somatic mutation of MutYH in Tunisian patients with sporadic colorectal cancer.

The MutYH gene is an adenine-specific DNA glycosylase that prevents G/T transversions. Germline mutation in this gene causes MYH-associated polyposis (MAP) that predispose to hereditary colorectal cancer (CRC). This study describes for the first time the association of the MutYH mutation with sporadic CRC.