Finally, individuals with comorbid conditions may exhibit a specific subset of symptoms. The evaluation of GTS symptoms in 410 GTS patients utilizing principal component analysis found that individuals who have GTS comorbid with ADHD or OCD are more likely to exhibit socially inappropriate behaviors and other complex vocal tics [40]. Further family studies of GTS–ascertained probands which would include GTS only, OCD only, ADHD only, comorbid GTS and ADHD, comorbid GTS and OCD, and comorbid GTS/OCD/ADHD probands and their relatives would help in understanding of the genetics of GTS and its comorbid disorders.
