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IEMbase 0114: UROD-related hepatic uroporphyrinogen decarboxylase deficiency

Scope

Field Value
IEMbase ID 114
Nosology 17.1.06.01
Gene UROD
External IDs OMIM:176100; ORPHA:95159
Generated mapping UNMAPPED
Candidate DisMech targets Inherited_Porphyria.yaml#Familial Porphyria Cutanea Tarda; Inherited_Porphyria.yaml#Hepatoerythropoietic Porphyria
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as UROD-related hepatic uroporphyrinogen decarboxylase deficiency, with alternate labels porphyria cutanea tarda type I, II and III, hepatoerythropoietic porphyria, and PCT. Treatability is marked yes.

The characteristic biochemical rows are increased heptacarboxylporphyrin in plasma and urine, increased total porphyrins in plasma and urine, and increased urocarboxylporphyrin in plasma and urine. The only clinical row is liver dysfunction. Hemin is listed as pharmacological treatment.

DisMech phenotype coverage

The generated unmapped status is partly a false negative. Inherited_Porphyria.yaml already includes both UROD-related subtypes relevant to the IEMbase label: familial porphyria cutanea tarda and hepatoerythropoietic porphyria. The local entry captures UROD pathogenic variants, bullous photodermatitis/cutaneous photosensitivity, and biallelic UROD-related hepatoerythropoietic porphyria.

However, DisMech does not yet provide a standalone PCT model and does not expose the IEMbase biochemical pattern of urinary/plasma heptacarboxylporphyrin and urocarboxylporphyrin as discrete biomarkers.

Concordance and completeness

Judgement: false negative to existing subtype-level coverage, but the IEMbase entity spans multiple UROD-related clinical categories.

The local entry is concordant for UROD-related PCT/HEP as inherited porphyria subtypes and is stronger for disease-mechanism classification. IEMbase is more specific for the diagnostic porphyrin fraction profile and liver-dysfunction row. The treatment listing is discordant or at least suspicious for routine PCT: hemin is a core acute hepatic porphyria therapy, whereas PCT management commonly requires a separate treatment review rather than automatic inheritance from acute porphyria treatment.

Curation actions

  • Resolve to Inherited_Porphyria.yaml#Familial Porphyria Cutanea Tarda and #Hepatoerythropoietic Porphyria rather than leaving this as no target.
  • Review whether the local PCT/HEP subtype split needs a standalone PCT entry or richer subtype-specific phenotypes.
  • Add or review UROD-specific biochemical markers before importing IEMbase's hemin treatment row.