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IEMbase 0111: UROS-related uroporphyrinogen III synthase deficiency

Scope

Field Value
IEMbase ID 111
Nosology 17.1.05.01
Gene UROS
External IDs OMIM:263700; ORPHA:79277
Generated mapping MAPPED, high confidence
Candidate DisMech targets Inherited_Porphyria.yaml#Congenital Erythropoietic Porphyria
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as UROS-related uroporphyrinogen III synthase deficiency, with alternate labels congenital erythropoietic porphyria, uroporphyrinogen cosynthase deficiency, and CEP. Treatability is marked yes.

The characteristic biochemical rows are increased type I porphyrin isomers in plasma and urine and increased total porphyrins in plasma and urine across all ages. The clinical rows are red-brown urine with pink fluorescence and intrinsic dental staining. The treatment row is avoidance of sunlight.

DisMech phenotype coverage

Inherited_Porphyria.yaml has a congenital erythropoietic porphyria subtype anchored to UROS. The local entry models UROS loss in erythroid heme synthesis, uroporphyrin I and coproporphyrin I accumulation, visible-light phototoxicity, chronic hemolytic anemia, thrombocytopenia, corneal scarring, and cutaneous photosensitivity.

DisMech also includes management context that is broader than IEMbase: photoprotection and bone marrow or hematopoietic stem cell transplantation for severe CEP.

Concordance and completeness

Judgement: correct subtype-level mapping with complementary detail.

The mapping is concordant for UROS/CEP and for the photosensitive porphyrin accumulation phenotype. DisMech is more complete for mechanism, hematologic complications, corneal involvement, and transplant-level treatment. IEMbase is more granular for the specific laboratory pattern of type I porphyrin isomers in plasma and urine and for dental staining/red-brown fluorescent urine, which are not represented as discrete local phenotype rows.

Curation actions

  • Keep the current target as Inherited_Porphyria.yaml#Congenital Erythropoietic Porphyria.
  • Consider adding CEP-specific biochemical rows for plasma/urinary type I porphyrin isomers.
  • Consider explicit phenotype review for erythrodontia/dental staining and red-brown fluorescent urine.