MLH1 constitutional and somatic methylation in patients with MLH1 negative tumors fulfilling the revised Bethesda criteria.

ABSTRACT: Lynch syndrome (LS) is a tumor predisposing condition caused by constitutional defects in genes coding for components of the mismatch repair (MMR) apparatus. While hypermethylation of the promoter of the MMR gene MLH1 occurs in about 15% of colorectal cancer samples, it has also been observed as a constitutional alteration, in the absence of DNA sequence mutations, in a small number of LS patients. In order to obtain further insights on the phenotypic characteristics of MLH1 epimutation carriers, we investigated the somatic and constitutional MLH1 methylation status of 14 unrelated subjects with a suspicion of LS who were negative for MMR gene constitutional mutations and whose tumors did not express the MLH1 protein. A novel case of constitutional MLH1 epimutation was identified. This pat

SUBMITTER: Crucianelli F 

PROVIDER: S-EPMC4622593 | biostudies-literature | 2014 Oct

REPOSITORIES: biostudies-literature