HMBS
Chr 11ARADhydroxymethylbilane synthase
Also known as: ENCEP, LENCEP, PBG-D, PBGD, PORC, UPS
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]
Primary Disease Associations & Inheritance
Clinical highlights
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly LoF-intolerant (top ~10% of genes)
Mild missense constraint
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
HMBS · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
External Resources
Links to major genomics databases and tools