Biallelic MUTYH mutations can mimic Lynch syndrome.

ABSTRACT: The hallmarks of Lynch syndrome (LS) include a positive family history of colorectal cancer (CRC), germline mutations in the DNA mismatch repair (MMR) genes, tumours with high microsatellite instability (MSI-H) and loss of MMR protein expression. However, in ∼10-15% of clinically suspected LS cases, MMR mutation analyses cannot explain MSI-H and abnormal immunohistochemistry (IHC) results. The highly variable phenotype of MUTYH-associated polyposis (MAP) can overlap with the LS phenotype, but is inherited recessively. We analysed the MUTYH gene in 85 'unresolved' patients with tumours showing IHC MMR-deficiency without detectable germline mutation. Biallelic p.(Tyr179Cys) MUTYH germline mutations were found in one patient (frequency 1.18%) with CRC, urothelial carcinoma and a sebaceous gla

SUBMITTER: Morak M 

PROVIDER: S-EPMC4200426 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature