[The relation between metabolism of biopterin and dystonia-parkinsonism].

Abstract

Tetrahydrobiopterin (BH4) is an essential cofactor for tyrosine hydroxylase. BH4 can be synthesized from GTP through three enzymatic reactions. The rate-limiting step of the BH4 synthesis is catalyzed by GTP cyclohydrolase I (GCH). Recently, we found that GCH is a causative gene for hereditary progressive dystonia/dopa-responsive dystonia (HPD/DRD). However, several problems still remain to be solved. The first concern is the presence of asymptomatic carriers in the disease. The difference between symptomatic and asymptomatic carriers is unknown. Second, we cannot find any mutation in the coding region of the GCH gene in about 40% of the patients. What kind of mutation would be present in these patients. The last concern is the molecular mechanism how the enzymatic activity is decreased to less than 20% of normal values. Further studies are required to solve the questions.

• Authors: H Ichinose, T Ohye, T Suzuki, H Inagaki, T Nagatsu
• Journal: Nihon shinkei seishin yakurigaku zasshi = Japanese journal of psychopharmacology (Nihon Shinkei Seishin Yakurigaku Zasshi) Vol. 19 Issue 2 Pg. 85-9 (Apr 1999) ISSN: 1340-2544 [Print] Japan
• PMID: 10464780 (Publication Type: English Abstract, Journal Article)

Chemical References

• Biopterin
• GTP Cyclohydrolase
• sapropterin
• Dopamine

Topics

• Animals
• Biopterin (analogs & derivatives, metabolism)
• Chromosomes, Human, Pair 14
• Dopamine (metabolism)
• Dystonia (genetics)
• GTP Cyclohydrolase (genetics)
• Heterozygote
• Humans
• Parkinson Disease (genetics)
• Substantia Nigra (metabolism)