Our group and others have reported on copy number variations (CNVs) in TD (Fernandez et al., 2012; McGrath et al., 2014; Nag et al., 2013; Sundaram et al., 2010), confirming a role for rare structural variants and showing a trend toward enrichment of de novo events. These findings also provide additional support for the involvement of histaminergic neurotransmission, as well as dopaminergic neurotransmission, in the pathogenesis of TD (Ercan-Sencicek et al., 2010; Fernandez et al., 2012) and suggest a potential overlap with CNVs contributing to other neurodevelopmental syndromes (Malhotra and Sebat, 2012).
