| Gilles de la Tourette Syndrome (TS) is a hereditary, neuropsychiatric disorder characterized both by chronic motor and vocal tics as well as associated behavioral and emotional problems. The prevalence of this condition is 0.3(8) to 0.5(4,5) per 1000. The National Institutes of Health suggests an estimate of 100,000 Americans afflicted with TS. TS is three to four times more common in adult males than in females and up to nine times more common in male than female children. TS is currently classified as being multifactorial, with both genetic and environmental influences that modify the clinical expression of the disorder. Many researchers believe that individuals may inherit a susceptibility to a spectrum disorder that includes TS, obsessive-compulsive behavior/disorder (OCB/OCD) and perhaps attention deficit hyperactivity disorder (ADHD). Extensive linkage analysis studies conducted on large families have identified at least three regions of the genome that may contain the TS locus. This thesis describes the social and clinical implications as well as the history, prevalence, diagnosis, clinical phenomology, associated conditions, neurobiology, genetics, treatment and the role of the genetic counselor for this complex condition. |
