HNMT, Official Symbol HNMTprovided by HGNC Official Full Name histamine N-methyltransferaseprovided by HGNC Primary source HGNC:HGNC:5028 See related Ensembl:ENSG00000150540 MIM:605238; AllianceGenome:HGNC:5028 Gene type protein coding RefSeq status REVIEWED Organism Homo sapiens Lineage Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae; Homo Also known as HMT; MRT51; HNMT-S1; HNMT-S2 Summary In mammals, histamine is metabolized by two major pathways: N(tau)-methylation via histamine N-methyltransferase and oxidative deamination via diamine oxidase. This gene encodes the first enzyme which is found in the cytosol and uses S-adenosyl-L-methionine as the methyl donor. In the mammalian brain, the neurotransmitter activity of histamine is controlled by N(tau)-methylation as diamine oxidase is not found in the central nervous system. A common genetic polymorphism affects the activity levels of this gene product in red blood cells. Multiple alternatively spliced transcript variants that encode different proteins have been found for this gene. [provided by RefSeq, Jul 2008] Expression Ubiquitous expression in liver (RPKM 20.0), fat (RPKM 16.4) and 24 other tissues See more Orthologs mouse all