New research identifies many genes contributing to Tourette syndrome

As part of a meta-analysis of multiple studies into Tourette’s syndrome (TS), a neurological disorder causing involuntary tics, researchers have identified hundreds of genes that contribute to the development of the disorder.

The study, led by researchers at the University of California at Los Angeles (UCLA), the University of Florida, Massachusetts General Hospital (MGH), and Purdue University, looked at results of 4,819 patients with TS and 9,500 controlled participants without the condition. The data were gathered from genome-wide association studies (GWAS).

In a secondary analysis of data, researchers compared over 700 patients with TS to more than 450 with other tic disorders along with a control group of 6,000 non-TS patients. In the findings, multiple gene variants were spotted which linked to a heightened risk of TS.

“Use of an aggregated polygenic risk score based on the identified risk variants to analyze every individual in the study – both with and without TS, as well as individuals with less severe tic disorders – confirmed that those inheriting more risk variants had more severe symptoms. However, the presence of TS-associated variants was not restricted to those with tic disorders,” the study found.

“Every one of the variants that contribute to developing TS is present in a significant proportion of the general population, which means that most people with TS do not have ‘broken’ or ‘mutated’ genes,” said Jeremiah Scharf, Ph.D., co-author of the study.

“The movements and thoughts that individuals with TS have are the same ones that all of us have, but just to a greater degree. As doctors and researchers, we know that there is nothing that separates those with TS from other children and adults, and now we’ve shown this is actually true on a genetic level.”

“This study is an example of the great impact of collaborative research in order to be able to finally understand the cause of complex disease,” said Peristera Paschou, a professor at Purdue University and co-author of the study.

“As a next step, we are now expanding analysis to an even larger sample of close to 12,000 patients with TS, again made possible thanks to widespread international collaboration. We hope that this will yield even higher power to further clarify the genetics of TS.”

The study was published in the American Journal of Psychiatry.