GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the conversion of GTP to D-erythro-7,8-dihydroneopterin triphosphate, the first and rate-limiting step in tetrahydrobiopterin (BH4) biosynthesis. Tetrahydrobiopterin is an essential cofactor for 3 aromatic amino acid monooxygenases: phenylalanine, tyrosine, and tryptophan hydroxylases.

A number sign (#) is used with this entry because dopa-responsive dystonia, or autosomal dominant Segawa syndrome, is caused by heterozygous mutation in the gene encoding GTP cyclohydrolase I (GCH1; 600225) on chromosome 14q13.

Oct 25, 2012 · An autosomal dominant form of Segawa syndrome (128230) is caused by mutation in the GCH1 gene (600225). Segawa syndrome is an autosomal recessive neurologic disorder characterized by onset in infancy of dopa-responsive dystonia.

Oct 28, 2003 · Glutaric aciduria type 1 (OMIM 231670) caused by glutaryl-CoA-dehydrogenase deficiency is associated with gliosis and neuronal loss in the basal ganglia resulting in dystonia [Harting et al 2009].

GTPCH (GCH1) and tetrahydrobiopterin were found to protect against cell death by ferroptosis. Tetrahydrobiopterin (BH 4) acts as a potent, diffusable antioxidant that resists oxidative stress and enables cancer cell survival.

Oct 23, 2017 · GCH1 is the gene responsible for the first, and rate-limiting, step in producing tetrahydrobiopterin (BH4), which is used as a cofactor in the production or conversion of several neurotransmitters. Please note that reference GCH1 sequences use the reverse strand.

Jan 9, 2021 · Gene target information for GCH1 - GTP cyclohydrolase 1 (human). Find diseases associated with this biological target and compounds tested against it in bioassay experiments.

Chromosomal location: 14q22.2 OMIM: 600225 HGNC: 4193 UniProtKB: P30793 Genatlas: GCH1

Mar 30, 2025 · GCH1 (GTP Cyclohydrolase 1) is a Protein Coding gene. Diseases associated with GCH1 include Hyperphenylalaninemia, Bh4-Deficient, B and Dystonia, Dopa-Responsive. Among its related pathways are tetrahydrobiopterin de …

Jul 2, 2014 · Mutations in GCH1 are the most common cause of DOPA-responsive dystonia (DYT5; OMIM#128230) (Clot et al., 2009), a rare movement disorder that presents typically in childhood with lower limb dystonia and subsequent generalization (Nygaard, 1993 b).