Germline deletion of the 3' portion of the Epithelial Cell Adhesion Molecule (EPCAM) gene located 5' upstream of MutS Homolog 2 (MSH2) is a novel mechanism for its inactivation in Lynch syndrome.
We found a novel large EPCAM-MSH2 duplication associated with LS and the presence of LOHs in regions containing numerous tumor suppressors, raising the hypothesis that these alterations could contribute to cancer susceptibility.
Recent studies have shown that some Lynch syndrome cases are due to 3' EPCAM/TACSTD1 deletions that subsequently lead to MSH2 promoter hypermethylation.
Using data from the Colon Cancer Family Registry, we compared the proportion of childhood cancers (diagnosed before 18 years of age) in the first-, second-, and third-degree relatives of 781 probands with a pathogenic mutation in one of the MMR genes; MLH1 (n = 275), MSH2 (n = 342), MSH6 (n = 99), or PMS2 (n = 55) or in EPCAM (n = 10) (Lynch syndrome families), with that of 5073 probands with MMR-deficient colorectal cancer (non-Lynch syndrome families).