Objective: Previous studies have demonstrated a relationship between obsessive-compulsive disorder or behavior and Gilles de la Tourette syndrome. It has been hypothesized that the serotonergic system is implicated in the etiology of obsessive-compulsive disorder. Therefore, the authors investigated whether genetic variation in a serotonergic receptor and a modifying enzyme were associated with Tourette's syndrome.
Method: A linkage analysis using DNA and blood group markers was carried out in a large British kindred multiply affected with Tourette's syndrome, chronic motor tics, and obsessive-compulsive behavior.
Results: There was no evidence to support the hypothesis that genetic variation in the serotonin 5-HT1A receptor and tryptophan oxygenase genes causes susceptibility to Tourette's syndrome and chronic multiple tics.
Conclusions: The results eliminate two possible candidate genes from having a role in the pathophysiology of Tourette's syndrome.