Tyrosine Hydroxylase Deficiency
You are reading a NORD Rare Disease Report Abstract. NORD’s full collection of reports on over 1200 rare diseases is available to subscribers (click here for details). We are now also offering two full rare disease reports per day to visitors on our Web site.
NORD is very grateful to Michèl Willemsen, MD, Pediatric Neurologist, Nijmegen, The Netherlands, for assistance in the preparation of this report.
Synonyms of Tyrosine Hydroxylase Deficiency
- autosomal recessive dopa-responsive dystonia
- autosomal recessive infantile Parkinsonism
- autosomal recessive Segawa syndrome
- TH deficiency
- tyrosine hydroxylase-deficient dopa-responsive dystonia (TH-DRD)
- No subdivisions found.
Tyrosine hydroxylase deficiency is a rare genetic disorder characterized by a wide spectrum of disease ranging from a mild movement disorder at one end to a life-threatening, neurological disorder at the other. The symptoms of the disorder can vary widely from person to another, even among members of the same family. Common symptoms include an uncoordinated or clumsy manner of walking (abnormal gait) and dystonia. Dystonia is a general term for a group of muscle disorders generally characterized by involuntary muscle contractions that force the body into abnormal, sometimes painful, movements and positions (postures). Dystonia in tyrosine hydroxylase deficiency usually affects the legs. Additional symptoms that may occur include tremors, eye abnormalities, weakness on one side of the body and a tendency of affected children to walk on their tiptoes. The severe form of tyrosine hydroxylase deficiency causes symptoms at a very young age (first months of life). The symptoms generally do not resemble those of a movement disorder, but rather give the impression of a severe, diffuse brain disorder. Mild and moderate forms of tyrosine hydroxylase deficiency show dramatic improvement when treated with levodopa. Levodopa is an amino acid that is converted to dopamine. Dopamine is a brain chemical that serves as a neurotransmitter and is deficient in children with tyrosine hydroxylase deficiency. Treatment options for severe tyrosine hydroxylase deficiency have been less effective. Tyrosine hydroxylase deficiency occurs due to disruptions or changes (mutations) of the TH gene. The TH gene mutation is inherited as an autosomal recessive trait.
Organizations related to Tyrosine Hydroxylase Deficiency
The information in NORD’s Rare Disease Database is for educational purposes only. It should never be used for diagnostic or treatment purposes. If you have questions regarding a medical condition, always seek the advice of your physician or other qualified health professional. NORD’s reports provide a brief overview of rare diseases. For more specific information, we encourage you to contact your personal physician or the agencies listed as “Resources” on this report.
The National Organization for Rare Disorders (NORD) web site, its databases, and the contents thereof are copyrighted by NORD. No part of the NORD web site, databases, or the contents may be copied in any way, including but not limited to the following: electronically downloading, storing in a retrieval system, or redistributing for any commercial purposes without the express written permission of NORD. Permission is hereby granted to print one hard copy of the information on an individual disease for your personal use, provided that such content is in no way modified, and the credit for the source (NORD) and NORD’s copyright notice are included on the printed copy. Any other electronic reproduction or other printed versions is strictly prohibited.
NORD's Rare Disease Information Database is copyrighted and may not be published without the written consent of NORD.