HMBS, Official Symbol HMBSprovided by HGNC Official Full Name hydroxymethylbilane synthaseprovided by HGNC Primary source HGNC:HGNC:4982 See related Ensembl:ENSG00000256269 MIM:609806; AllianceGenome:HGNC:4982 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 UPS; PBGD; PORC; PBG-D Summary This gene encodes a member of the hydroxymethylbilane synthase superfamily. The encoded protein is the third enzyme of the heme biosynthetic pathway and catalyzes the head to tail condensation of four porphobilinogen molecules into the linear hydroxymethylbilane. Mutations in this gene are associated with the autosomal dominant disease acute intermittent porphyria. Alternatively spliced transcript variants encoding different isoforms have been described. [provided by RefSeq, Jul 2008] Expression Biased expression in bone marrow (RPKM 55.8), colon (RPKM 5.0) and 13 other tissues See more Orthologs mouse all