porphyria, acute intermittent, nonerythroid variant
Findings
No curated finding names porphyria, acute intermittent, nonerythroid variant yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
A HMBS-related hepatic porphyria subtype caused by variants in HMBS exon 1, which is not expressed in erythrocytes, causing HMBS activity in erythrocytes to be at a normal level. The housekeeping promoter produces the HMBS transcript containing exons 1 and 3-15. In contrast, erythrocytes use an erythroid-specific promoter downstream of the housekeeping HMBS promoter to produce a transcript that contains only exons 2-15. Therefore deleterious variants occurring within exon 1 or affecting the splicing of exon 1 to exon 3 do not impact the erythrocyte isozyme, but do impact the more broadly expressed housekeeping isozyme.
Definition from the Mondo Disease Ontology (MONDO:0700384), read 2026-09-29. CC BY 4.0.
Where it sits
- A kind of