Searching for Tourette’s syndrome gene. Part 1. Heterogeneity of clinical phenotypes

The French neuropsychiatrist Georges Gilles de la Tourette described in 1885 the “Maladie des Tics” which later was named after him, as Gilles de la Tourette syndrome (GTS). Gilles de la Tourette syndrome is a neurodevelopmental disorder characterized by simple and complex motor and vocal tics with multiple neuropsychiatric comorbidities. GTS is often concurrent with obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD). There are several clinical GTS subtypes: GTS only, GTS OCD, and GTS OCD ADHD. Additional clinical aspects of the disorder include occurrence of anger episodes, anxiety and mood disorders, and learning and sleeping disturbances. The genetics of GTS is complex and remains unclear. So far, no causative candidate genes have been identified. However, segregation studies in families and twins with GTS provide strong evidence for the existence of a genetic background associated with a multifactorial mode of inheritance. Progress in studies on genome variability among patients with GTS is necessary to improve pharmacotherapeutic strategies of the disorder.