| Mismatch repair cancer syndrome | |
|---|---|
| Other names | Brain tumor-polyposis syndrome, Glioma-polyposis syndrome |
| | |
| This condition is inherited in an autosomal recessive manner | |
| Specialty | Oncology |
Mismatch repair cancer syndrome (MMRCS) is a cancer syndrome associated with biallelic DNA mismatch repair mutations. [1] It is also known as Turcot syndrome (after Jacques Turcot, who described the condition in 1959) and by several other names. [1]
In MMRCS, neoplasia typically occurs in both the gut and the central nervous system (CNS). [1] In the large intestine, multiple colonic polyps develop; in the CNS, brain tumors.
Under the name constitutional mismatch repair-deficiency (CMMR-D), it has been mapped to MLH1, MSH2, MSH6 or PMS2. [2] Monoallelic mutations of these genes are observed in the condition known as Lynch syndrome or hereditary nonpolyposis colorectal cancer, while biallelic mutations are observed in CMMR-D. [3] People expressing the HNPCC (which itself is considered autosomal dominant) trait are considered carriers of CMMR-D, thus CMMR-D is classified as autosomal recessive.[ citation needed ]
The term "childhood cancer syndrome" has also been proposed. [4] [5] Café-au-lait macules have been observed. [6]
Childhood to early adult onset HNPCC + malignant gliomas. The polyps developed tend to be larger, fewer, and progress to malignancy earlier than those seen in familial adenomatous polyposis, [1] a clinically similar condition with different underlying mutations. Diagnostic testing consists of a blood sample being collected, and a genetic specialist compares two copies of a patient's gene to normal MMR genes. If there are differences in the genes, the specialists are able to further test and decide if the patient has the deficiency. [7]
OMIM currently includes "Turcot syndrome" under Mismatch repair cancer syndrome. Turcot syndrome is the association between familial polyposis of the colon and brain tumors [8] like medulloblastoma, malignant glioma. It was first reported by Canadian surgeon Jacques Turcot (1914-1977 ) et al. in 1959 and hence carries the first author's name. [9]