{{Rsnum
|rsid=7164342
|Gene=GCHFR
|Chromosome=15
|position=40763169
|Orientation=plus
|GMAF=0.3627
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(G;G)
|geno2=(G;T)
|geno3=(T;T)
|Gene_s=GCHFR
}}A polymorphism of the GTP-cyclohydrolase I feedback regulator gene alters transcriptional activity and may affect response to SSRI antidepressants.{{PMID|20351752}}