Tourette Syndromes & Genetics

Frequent Questions

The risk factors cited here arise from supremely careful and complicated analyses of family histories taken from hundreds of families, not unlike the readers. This way of determining probabilities is called a “study of empirical risk data.” Since there is no test to diagnose TS, this is the method that expert genetic professionals should use.

Q. What is the chance of a child having TS or one of its related disorders if their parent has TS?

Suppose the parent has TS and comes from a family where other members have TS or one of their related conditions, the risk that their child will have TS or one of its related conditions increases. The danger is different for boys and girls. Specifically, the chance of a child developing TS is about 10–15%. But in addition, the probability of chronic tics is about 15–20%, and the chance that you will have COC without tics is about 5–10%. Thus, the average risk of a child developing something within the TS spectrum is approximately 40–45%. A daughter’s risk is approximately 3–5% for TS, 10–15% for chronic tics, and 10–20% for COC without tics. The average risk for a daughter is approximately 25–35%.

These risk factors increase seriously when both parents have TS and OCD. In this situation, the offspring acquiring TS can reach 25–50%, with the risk of…