Turcot Syndrome

**Semantic type:** Disease or Syndrome

**Definition:** An autosomal dominant hereditary neoplastic syndrome caused by mutations in the PMS2, MLH1, MSH2, or APC genes. There are two types described, type 1, characterized by the presence of glioblastoma and often associated with hereditary nonpolyposis colorectal carcinoma, and type 2, characterized by the presence of medulloblastoma and familiar adenomatous polyposis.