Neuromotor and cognitive outcomes of early treatment in tyrosine hydroxylase deficiency type B

Tyrosine hydroxylase deficiency (THD) is an autosomal recessive disorder resulting in severe dopamine depletion, with fewer than 70 patients diagnosed worldwide.1 Most of the reported cases of THD belong to 2 phenotypes: an infantile progressive hypokinetic-rigid syndrome with dystonia (type A) and a neonatal/early-onset severe encephalopathy (type B).1 Given the early onset, the extensive involvement of neurologic development, and the limited response to dopaminergic medications, prognosis for THD type B is poor.1–6 Twenty patients with THD type B have been described so far, with no data on long-term outcome.1,2 We report follow-up lasting 17 years with serial video recordings of the index case of THD type B.1,2,7 Acknowledgment: The authors thank Dr. Carlo Dionisi-Vici, Unit of Metabolism, Bambino Gesù Children's Hospital, Rome, for his contribution to the clinical management of the patient and Dr. Claudia Carducci, Department of Experimental Medicine, Sapienza University of Rome, who performed all the biochemical investigations.