Candidate locus for Gilles de la Tourette syndrome/obsessive compulsive disorder/chronic tic disorder at 18q22.

Gilles de la Tourette syndrome (GTS), obsessive compulsive disorder (OCD), and chronic tic disorder (CTD) are chronic, potentially debilitating neuropsychiatric disorders that often cluster in families. Comorbidity data and family and linkage studies support the hypothesis that these phenotypes, in some cases, share a common etiology. Studies of chromosomal abnormalities associated with this phenotypic spectrum further show that GTS, OCD, and CTD may represent alternate manifestations of a shared genetic condition. We report on a 14-year-old girl with severe OCD and a t(2;18)(p12;q22) translocation. The patient's chromosome 18 breakpoint localizes to the same chromosomal band as two previously reported rearrangements associated with GTS, OCD, and CTD, and fine maps to a genomic position approximately 5 Mb from these rearrangements. The clustering of these three breakpoints within a relatively small genetic interval suggests that 18q22 is a promising region for containing a gene or genes of etiologic importance in the development of the GTS/OCD/CTD phenotypic spectrum.