A large Italian family with Gilles de la Tourette syndrome: clinical study and analysis of the SLITRK1 gene.

Our objective was to report the clinical characteristics and to investigate the role of SLITRK1 gene in a large Italian family with Tourette syndrome (TS). The diagnosis of TS and chronic motor tics (CMT) was made according to "The Tourette Syndrome Classification Study Group" (1993). Psychiatric diagnoses were made by administering the Structured Clinical Interview for DSM and the Yale-Brown Obsessive Compulsive Scale. Genetic study included direct sequencing and copy number analysis of the SLITRK1 gene, and haplotype analysis. We found tics or other behavioral manifestations in 15 subjects. Of these, 5 received a diagnosis of definite TS, 5 were classified as having definite CMT, 2 had definite nonspecific tic disorder, and 3 patients had obsessive-compulsive disorder without motor or phonic tics. Tics mainly involved the craniocervical district. Many patients with tics had coexisting psychiatric disorders, especially obsessive-compulsive disorder, performed poorly at school and had social problems. Direct sequencing and copy number analysis of the SLITRK1 gene, and haplotype analysis suggested that the SLITRK1 locus was not involved in this family. In conclusion, the distinctive clinical features in this family are the motor tics mainly involving the face and the neck and the severe coexisting psychiatric disorders. The negative results of the SLITRK1 analysis point to genetic heterogeneity in TS.