A patient with four metachronous cancers and multiple adenomatous colon polyps harboring the American Founder Lynch syndrome mutation: a case report

Background Lynch syndrome (LS) is a genetic disorder that accounts for approximately 3% of all colorectal cancers (CRC) [1]. Clinical characteristics of LS include proximal CRC, multiple CRCs, occurrence at a young age, accelerated carcinogenesis, and an increase in risk of extracolonic cancers [1]. LS is an autosomal dominant disorder, caused by germline mutations in DNA mismatch repair (MMR) genes. Mutations in MSH2 account for 1-2% of all CRCs and up to 20% of these are large germline deletions [2]. The MSH2 deletion of exons 1-6 has been characterized as a North American Founder Mutation (AFM) [2,3].