{{Rsnum
|rsid=3783641
|Gene=GCH1
|Chromosome=14
|position=54893421
|Orientation=plus
|GMAF=0.2309
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(A;A)
|geno2=(A;T)
|geno3=(T;T)
|Gene_s=GCH1
}}{{ population diversity
| geno1=(A;A)
| geno2=(A;T)
| geno3=(T;T)
| CEU | 6.5 | 37.1 | 56.5
| HCB | 2.2 | 28.9 | 68.9
| JPT | 6.8 | 27.3 | 65.9
| YRI | 11.1 | 60.3 | 28.6
| ASW | 0.0 | 0.0 | 0.0
| CHB | 2.2 | 28.9 | 68.9
| CHD | 0.0 | 0.0 | 0.0
| GIH | 0.0 | 0.0 | 0.0
| LWK | 0.0 | 0.0 | 0.0
| MEX | 0.0 | 0.0 | 0.0
| MKK | 0.0 | 0.0 | 0.0
| TSI | 0.0 | 0.0 | 0.0
| HapMapRevision=28
}}GTP cyclohydrolase and [[tetrahydrobiopterin]] regulate pain sensitivity and persistence. A allele associated with higher tolerance to pain.{{PMID|17057711}}

Polymorphisms in the GTP cyclohydrolase gene ([[GCH1]]) are associated with ratings of capsaicin pain. A allele associated with higher tolerance to pain.{{PMID|19081190|OA=1
}}

Do genetic predictors of pain sensitivity associate with persistent widespread pain? A allele associated with higher pain tolerance.{{PMID|19775452|OA=1
}}

[[GCH1]] haplotype determines vascular and plasma biopterin availability in coronary artery disease effects on vascular superoxide production and endothelial function. Part of a haplotype, [[rs10483639]](C)-[[rs3783641]](A)-[[rs8007267]](T), associated with lower levels of [[tetrahydrobiopterin]].{{PMID|18598896|OA=1
}}

{{PMID Auto
|PMID=17343757
|Title=Lack of influence of GTP cyclohydrolase gene (GCH1) variations on pain sensitivity in humans.
|OA=1
}}

{{PMID Auto
|PMID=17363416
|Title=Reliable screening for a pain-protective haplotype in the GTP cyclohydrolase 1 gene (GCH1) through the use of 3 or fewer single nucleotide polymorphisms.
}}

{{PMID Auto
|PMID=19014702
|Title=Does the pain-protective GTP cyclohydrolase haplotype significantly alter the pattern or severity of pain in humans with chronic pancreatitis?
|OA=1
}}

{{PMID Auto
|PMID=19751821
|Title=Oxidative risk for atherothrombotic cardiovascular disease.
|OA=1
}}

{{PMID Auto
|PMID=20633294
|Title=Different SNP combinations in the GCH1 gene and use of labor analgesia.
|OA=1
}}

{{PMID Auto
|PMID=20842020
|Title=Catecholamine-o-methyltransferase polymorphisms are associated with postoperative pain intensity.
}}

{{PMID Auto
|PMID=23059057
|Title=A GCH1 haplotype and risk of neural tube defects in the National Birth Defects Prevention Study
|OA=1
}}

{{PMID Auto
|PMID=22770721
|Title=GTP cyclohydrolase 1 gene haplotypes as predictors of SSRI response in Japanese patients with major depressive disorder
}}

{{PMID Auto
|PMID=23322459
|Title=Association of guanosine triphosphate cyclohydrolase 1 gene polymorphisms with fibromyalgia syndrome in a Korean population.
}}

{{on chip | 23andMe v1}}
{{on chip | 23andMe v2}}
{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}