Causes

In most cases, TS is inherited through a gene (or genes). However, some patients may have milder tic disorders or obsessive-compulsive symptoms with no tics. Sometimes there are no symptoms.

Genetic Material

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Some people with TS have no known family history of TS, tics, or obsessive-compulsive symptoms. Researchers are studying whether other factors, such as birth-related issues and autoimmune problems, may contribute to TS.

TS is one of the conditions grouped under the category Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal (or PANDAS). Studies suggests that, in some children, PANDAS are associated with Group A streptococcal or strep throat .

Researchers are studying whether the risk of PANDAS can be decreased by rapid treatment or prevention of strep infections. Also, studies need to be done to find out if some children are at a higher risk because of their genetic make-up. Overall, strep infection is common. So, if PANDAS are caused by the infection, then it's likely to occur only rarely.

Other than this possible connection, the cause of tics is unknown. However, studies show that several brain chemicals, called neurotransmitters, are involved. Dopamine and serotonin are most likely involved. In addition, stress and tension often increase tics.

Risk Factors

Tell your doctor if you have any of these risk factors:

• Family history of TS, other tic disorders, or obsessive-compulsive disorder
• Sex: male (three to four times more likely to be affected)
• Strep infection (may be a risk in some children)

There are many secondary causes of tics including:

• Hereditary disorders
• Carbon monoxide poisoning
• Traumatic brain injury
• Cerebral infections
• Medications
• Illegal drugs