Association of the Slit and Trk-like 1 gene in Taiwanese patients with Tourette syndrome.

Tourette syndrome is a neurologic disorder characterized by both motor and vocal tics. Recently, two variants, including a single-base deletion resulting in a truncated protein and a 3'-untranslated-region variant altering a binding site for micro-RNA in the Slit and Trk-like 1 gene, were found to be a genetic cause of Tourette syndrome. The Slit and Trk-like 1 family was identified as neuronal transmembrane proteins that control neurite outgrowth. This study aimed to determine whether mutations in the gene can be found in Taiwanese patients with Tourette syndrome. In total, 160 patients were included. All children underwent peripheral blood sampling for genotype analyses. We sequenced the whole Slit and Trk-like 1 gene, including the promoter, the 3'-untranslated region, the 5'-untranslated region, and the whole coding region. We found that none of the 160 samples revealed any mutation in the whole gene sequence. In addition, there was only one polymorphism, c.3225 T>C, detected in 10 individuals. We conclude that in rare variants, it may be difficult to establish an association with disorder. Therefore, genetic screening in the Slit and Trk-like 1 gene for the recently identified mutations does not appear to be of utility in the diagnosis of Tourette syndrome.