Overall, our results argue that, in addition to some shared genetic variants contributing to susceptibility of either TS or OCD, genetic variants likely exist which provide phenotypic specificity for each disorder. This observation contrasts with the hypothesis that genes contributing to neuropsychiatric disorders provide a “generalist” framework of neuronal connections from which non-genetic factors determine specific phenotypes, as has been proposed to explain the wide range of phenotypes observed in patients with similar large recurrent CNVs across various regions of the genome (34, 35). Furthermore, the apparent difference between OCD with and without tics supports the importance of detailed phenotypic characterization to identify future subtype-specific risk alleles. Collection of additional samples through ongoing collaboration will be crucial to further elucidate the specific underlying susceptibility genes for TS and OCD, both shared and unique.
