Rare inherited autosomal recessive disease with hemolytic anemia and marked skin photosensitivity.
Congenital erythropoietic porphyria is a rare, autosomal recessive disease caused by a mutation in the UROS gene, which encodes uroporphyrinogen III synthase.
Associated with marked deficiency of uroporphyrinogen III cosynthase activity.
This enzyme defect disrupts heme biosynthesis and leads to an accumulation of uroporphyrin in erythrocytes, which, in turn, increases their osmotic fragility and results in hemolysis.
Hemolytic anemia usually manifests at birth and is photosensitive in nature.
The classic primary manifestation of congenital erythropoietic porphyria is pink-red discoloration of the urine in infancy or childhood.
The clinical phenotype and severity of symptoms vary greatly and include nonimmune hydrops fetalis in utero, scarring and deformities, hemolytic anemia, corneal scarring, and blindness.
Hemolysis secondary to massive accumulation of isomer I uroporphyrin and coproporhyrin in red blood cells.
Erythrodontia is due the binding of excess porphyrin to calcium phosphate in dentin and enamel.
As erythropoietic activity increases it stimulates increased porphyrin production in the bone marrow.
Following splenectomy hemolysis may improve.
Clinically symptoms are indistinguishable from hepatoerythropoietic porphyria.