Genetic underpinnings of tardive dyskinesia: passing the baton to pharmacogenetics

Manifestation of tardive dyskinesia (TD) among schizophrenia subjects on long-term antipsychotic treatment with typical drugs has been a clinical concern. Despite its association with extrapyramidal symptoms, typical drugs are still routinely prescribed globally though marginally superior atypical drugs have long been available. The genetic component in the etiology of TD is well documented. Search for these determinants has led to a few consensus associations of CYP2D6 *10, CYP1A2*1F, DRD2 Taq1A (rs1800497), DRD3 Ser9Gly (rs6280) and MnSOD Ala9Val (rs4880) variants with TD. However, translation of these observations into the clinic has not been achieved so far. This review discusses the salient features of TD etiopathology, current status of TD genetics, interactions between genetic and nongenetic factors, some major drawbacks, challenges and expected focus in TD research over the next decade, with emphasis on pharmacogenetics.