TH and thanatophoric dysplasia: Recently, alpha methyl paratyrosine (AMPT), an inhibitor of TH, has been reported to be clinically efficacious in the treatment of antipsychotic-induced TD.12 Consequently, it has been suggested that the efficacy of AMPT in TD may be related to a downregulation of TH activity that may be increased by neuroleptic-induced effects on TH phosphorylation.12