Certain MMR gene mutations predispose to combined occurrence of cutaneous sebaceous gland neoplasms and visceral malignancies, which is known as Muir-Torre syndrome (MTS) and regarded as a phenotypic variant of HNPCC.
Hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome types I and II, and the related subtypes Turcot and Muir-Torre syndrome, have all been associated with inheritance of germ line mutations in the DNA mismatch repair (MMR) genes.
The eponymous Muir-Torre syndrome (MTS) is a clinical variant of hereditary non polyposis colorectal cancer, and is defined as an autosomal dominant condition with simultaneous sebaceous neoplasms of the skin and visceral malignant disease resulting from germline mutations in the DNA mismatch repair (MMR) genes.