GCH1 (GTP cyclohydrolase 1) variants and mutations

GCH1 (also known as GTP cyclohydrolase 1) is a human protein-coding gene encoding a GTP cyclohydrolase 1 protein. It catalyzes the rate-limiting step in tetrahydrobiopterin synthesis, supplying an essential cofactor for dopamine, serotonin, norepinephrine, and nitric-oxide production. Dominant loss-of-function variants classically cause dopa-responsive dystonia, while biallelic deficiency can produce severe neurotransmitter disease. This analysis covers 552 GCH1 variants and mutations. Of these, 94% have computational variant effect predictions. Disease context includes dystonia 5, GTP cyclohydrolase I deficiency with hyperphenylalaninemia, and Hyperphenylalaninemia. Example GCH1 variants include M1I, M1L, and M1V.

Variant analysis overview

Variant and mutation evidence

Clinical, disease, and population context

Protein structure and variant hotspots

Data sources

Evidence in this analysis draws on EBI Proteins Variation, UniProt, gnomAD v4, EuropePMC, 3D Hotspot Analysis, Interaction Network Analysis, Protein Data Bank, AlphaFold DB, gnomAD constraint, Open Targets, ClinGen, MaveDB, LitVar.

Notable GCH1 variants

Examples include M1I, M1L, M1V, M1T, E2K, G4D, G4R, G4S. Listed records include available protein-change notation, database identifiers, clinical classifications, computational predictions, population evidence, experimental measurements, and disease context.