Which are the causes of Turcot Syndrome?

Turcot Syndrome is a rare genetic disorder that is characterized by the development of certain types of tumors in the brain and the colon. It is an autosomal recessive condition, which means that an individual must inherit two copies of the mutated gene, one from each parent, in order to develop the syndrome. The syndrome is named after the Canadian physician Jacques Turcot, who first described it in 1959.

The primary cause of Turcot Syndrome is mutations in specific genes that are involved in the regulation of cell growth and division. The two main genes associated with the syndrome are APC (adenomatous polyposis coli) and MLH1 (mutL homolog 1). Mutations in the APC gene are responsible for the majority of cases, while mutations in the MLH1 gene are less common.

The APC gene provides instructions for producing a protein that helps control the growth and division of cells. Mutations in this gene lead to the production of a defective protein that is unable to regulate cell growth effectively. As a result, abnormal growths called polyps can develop in the colon. Over time, these polyps can become cancerous, leading to colorectal cancer.

The MLH1 gene is involved in DNA repair, specifically in the correction of errors that occur during DNA replication. Mutations in this gene impair the ability of cells to repair DNA damage, which can lead to the accumulation of genetic abnormalities. This genetic instability increases the risk of developing tumors, particularly in the brain.

It is important to note that Turcot Syndrome is a hereditary condition, meaning that it can be passed down from parents to their children. If both parents carry a mutated copy of the APC or MLH1 gene, each child has a 25% chance of inheriting two mutated copies and developing the syndrome.

While the exact causes of gene mutations in Turcot Syndrome are not fully understood, it is believed that a combination of genetic and environmental factors may play a role. Certain environmental exposures, such as radiation or certain chemicals, may increase the risk of gene mutations in susceptible individuals.

In conclusion, Turcot Syndrome is primarily caused by mutations in the APC or MLH1 genes, which are involved in cell growth regulation and DNA repair. These mutations lead to the development of tumors in the brain and colon. The syndrome is hereditary and can be passed down from parents to their children. While the exact causes of gene mutations are not fully known, environmental factors may also contribute to the development of the syndrome.