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Reviewed May 2012
What is the official name of the GCH1 gene?
The official name of this gene is “GTP cyclohydrolase 1.”
GCH1 is the gene's official symbol. The GCH1 gene is also known by other names, listed below.
Read more about gene names and symbols on the About page.
What is the normal function of the GCH1 gene?
The GCH1 gene provides instructions for making an enzyme called GTP cyclohydrolase 1. This enzyme is involved in the first of three steps in the production of a molecule called tetrahydrobiopterin (BH4). Other enzymes help carry out the second and third steps in this process.
Tetrahydrobiopterin plays a critical role in processing several protein building blocks (amino acids) in the body. For example, it works with the enzyme phenylalanine hydroxylase to convert an amino acid called phenylalanine into another amino acid, tyrosine. Tetrahydrobiopterin is also involved in reactions that produce chemicals called neurotransmitters, which transmit signals between nerve cells in the brain. Specifically, tetrahydrobiopterin is involved in the production of two neurotransmitters called dopamine and serotonin. Among their many functions, dopamine transmits signals within the brain to produce smooth physical movements, and serotonin regulates mood, emotion, sleep, and appetite. Because it helps enzymes carry out chemical reactions, tetrahydrobiopterin is known as a cofactor.
How are changes in the GCH1 gene related to health conditions?
Where is the GCH1 gene located?
Cytogenetic Location: 14q22.1-q22.2
Molecular Location on chromosome 14: base pairs 54,842,005 to 54,902,885
(Homo sapiens Annotation Release 107, GRCh38.p2) (
The GCH1 gene is located on the long (q) arm of chromosome 14 between positions 22.1 and 22.2.
More precisely, the GCH1 gene is located from base pair 54,842,005 to base pair 54,902,885 on chromosome 14.
See How do geneticists indicate the location of a gene? in the Handbook.
Where can I find additional information about GCH1?
You and your healthcare professional may find the following resources about GCH1 helpful.
You may also be interested in these resources, which are designed for genetics professionals and researchers.
What other names do people use for the GCH1 gene or gene products?
See How are genetic conditions and genes named? in the Handbook.
Where can I find general information about genes?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding GCH1?
acids ; amino acid ; cell ; cofactor ; deficiency ; disability ; dopamine ; dystonia ; enzyme ; gene ; GTP ; involuntary ; molecule ; mutation ; neurotransmitters ; phenylalanine ; protein ; toxic ; tyrosine
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (11 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.