Dope-responsive dystonia simulating spastic paraplegia due to tyrosine hydroxylase (TH) gene mutations

Spastic paraplegia is not widely recognized to occur in dopa-responsive dys tonia (DRD). The authors found a compound heterozygote for novel mutations of the human tyrosine hydroxylase (TH) gene (TH). The patient was initially diagnosed as having spastic paraplegia, but responded completely to levodo pa therapy. Exercise-induced stiffness in the patient's father, who had a T H deletion, also responded to levodopa. The data expand the clinical spectr um of TH deficiency and suggest that TH mutations may account for some pati ents with DRD simulating spastic paraplegia.