A preliminary exome sequence in three patients with tardive dystonia

Tardive dystonia is one of the most serious adverse events that can be caused by antipsychotic treatment, but few studies have examined the etiology of tardive dystonia, and no genetic study using a next-generation sequencing technique has been performed to date. We conducted exome sequencing in three subjects with severe tardive dystonia. We analyzed the results focusing on candidate genes of primary dystonia, for example, TOR1A, GCH1, TH, THAP1, and SGCE. There were no single-nucleotide polymorphisms of these dystonia genes that were commonly shared among our subjects. Instead, the results revealed the presence of rare mutations (minor allele frequency <0.01) on the ZNF806 and SART3 genes in all three patients. This is the first study to analyze whole-exonic regions of the genomes of patients with tardive dystonia. These results were only preliminary, but they suggest that subjects presenting with tardive dystonia induced by antipsychotic treatment can have a genetic predisposition to tardive dystonia.