User:Radhikabassi/sandbox

Turcot Syndrome (named after Jacques Turcot; 1959) also known as Mismatch repair cancer syndrome (MMRCS) is a rare, inherited disorder in which cells become abnormal and form masses called polyps. Polyps are benign (noncancerous) but can become malignant (cancerous), and spread to other parts of the body. Turcot syndrome is considered to be an alternative form of two other polyp formation syndromes: Lynch syndrome and familial adenomatous polyposis (FAP).

The two most common types of brain tumours in Turcot syndrome are:
 * 1) Glioblastoma. This is a progressive form of astrocytoma, which is a type of brain cancer originating from astrocytes. It is commonly found in families showing characteristics of Lynch syndrome.
 * 2) Medulloblastoma. This begins in the cerebellum and often occurs in children and families showing characteristics of FAP.

Genetics
Turcot syndrome is a genetic condition which can be passed down generation to generation. Families who have a history of glioblastoma and show characteristics of Lynch syndrome have mutations in the MLH1 and PMS2 genes. Both the MLH1 and PMS2 genes provide instructions for making proteins involved in DNA repair. The MLH1 and PM2S proteins join to form a protein complex. This complex coordinates activities of other proteins that repair mistakes made during DNA replication.

Families who have a history of medulloblastoma and show characteristics of FAP have mutations in the APC gene. The APC gene provides instructions for making the APC protein, which plays a key role in cellular processes. It acts as a tumour suppressor, stopping cells from growing and dividing uncontrollably.

Turcot syndrome is also linked to mutations in the MSH2 and MSH6 genes. The MSH2 and MSH6 genes provide instructions for making proteins involved in DNA replication. They join to form a protein complex, which identifies locations on the DNA where mistakes are being made. The MLH1-PMS2 protein complex then repairs the errors.

Diagnosis
Individuals are given a blood test to look for a mutation in the APC gene associated with FAP or the MLH1 gene associated with Lynch syndrome. Additionally, in suspected cases of Turcot syndrome, individuals may be tested for a mutation in the PMS2 gene.

If a gene mutation is detected, then the same genetic test is done with other family members to look for a common abnormality pattern. If a common pattern is detected, then it is inferred that the individual has Turcot syndrome. However, some individuals who appear to have Turcot syndrome may not have detectable gene mutations.

Aside from genetic tests, colonoscopy, biopsy of the tumor tissue and X-ray of the CNS for detecting brain tumour is conducted.

Treatment
Treatments start with screening for colon cancer using colonoscopy on a regular basis. The frequency and starting age is dependent on the gene mutation. People with APC gene mutation start colonoscopies at around 10. People with a MLH1 or PMS2 gene mutation start colonoscopies in their early 20s. They have one every one to two years. If there are polyps, individuals have a colectomy. Colectomy is when the colon or part of the colon is surgically removed.

Individuals with Turcot syndrome are encouraged to test for the presence of a brain tumour via neurological screening. The treatment of a brain tumor is specific to the size and type of brain tumour. It may include surgery to remove as much of the tumour as possible without damaging surrounding tissues. Radiation and/or chemotherapy treatments often follow surgery.

Genetic counseling is also offered to individuals and family members.

Synonyms

 * Brain tumor-polyposis syndrome
 * Glioma-polyposis syndrome

Related Diseases

 * Gardner syndrome is an association of hereditary intestinal polyps, osteomas (typically of the skull), papillary thyroid cancer, and desmoid tumors.
 * Peutz–Jeghers syndrome is a rare, inherited gastrointestinal disorder classified by polyps development on intestinal mucous lining and discoloration on the skin and mucous membranes.
 * Cronkhite–Canada syndrome is a rare gastrointestinal disorder classified by the formation of polyps in the intestines, loss of scalp hair, discoloration of patches of skin and loss of finger and/or toenails.