What are the genetic changes related to Tourette syndrome ?
A variety of genetic and environmental factors likely play a role in causing Tourette syndrome. Most of these factors are unknown, and researchers are studying risk factors before and after birth that may contribute to this complex disorder. Scientists believe that tics may result from changes in brain chemicals (neurotransmitters) that are responsible for producing and controlling voluntary movements.  Mutations involving the SLITRK1 gene have been identified in a small number of people with Tourette syndrome. This gene provides instructions for making a protein that is active in the brain. The SLITRK1 protein probably plays a role in the development of nerve cells, including the growth of specialized extensions (axons and dendrites) that allow each nerve cell to communicate with nearby cells. It is unclear how mutations in the SLITRK1 gene can lead to this disorder.  Most people with Tourette syndrome do not have a mutation in the SLITRK1 gene. Because mutations have been reported in so few people with this condition, the association of the SLITRK1 gene with this disorder has not been confirmed. Researchers suspect that changes in other genes, which have not been identified, are also associated with Tourette syndrome.