Tourette syndrome (TS) is a common neuropsychiatric disorder in children characterized by multiple motor and vocal tics that fluctuate in severity and lasting for at least 1 year. Boys are more commonly affected than girls. Symptoms usually begin with simple motor or vocal tics which then evolve into more complex motor and vocal tics over time. Premonitory sensory urges are common in children over the age of 8 years, and these urges help distinguish tics from symptoms of other movement disorders. Common comorbidities of TS include attention deficit hyperactivity disorder, obsessive-compulsive disorder and learning difficulties. Several genes have been assessed as candidate genes for TS; environmental factors such as stress and streptococcal...