Answer

Do You Know Someone who is Sensitive to Sunlight? They may have Congenital Erythropoietic Porphyria

What it is In Brief

            By now you must have learnt that congenital erythropoietic porphyria (CEP) is a chronic and rare genetic disorder that develops due to deficiency of uroporphyrinogen III synthase, which is the fourth enzyme in the haem biosynthetic pathway (Di-Pierro, Brancaleoni, & Granata, 2016). Enzyme defect leads to overproduction of pathogenic and non-physiological porphyrin isomers, coproporhyrin I, and uroporphyrin I. CEP is inherited as X-linked trait or autosomal recessive trait due to mutations in GATA1 or UROS genes (Di-Pierro, Brancaleoni, & Granata, 2016).

Signs and Symptoms

            Clinical manifestations of CEP include bullous cutaneous photosensitivity to light at the visible spectrum from early infancy, chronic hemolytic anemia, and progressive photomutilation. The disorder may lead to death in utero and fetal hydrops (Di-Pierro, Brancaleoni, & Granata, 2016). CEP patients may experience increased skin fragility over areas exposed to sun light. Other manifestations include pink to dark urine and reddish discoloration of teeth (Erwin, Balwani, & Desnick, 2016).

Diagnostic Strategy

Laboratory investigation includes biochemical tests to detect markedly decreased uroporphyrinogen synthase activity in erythrocytes. In addition, elevated levels of coproporphyrin I and uroporphyrin I isomers are also indicative of the disease. CEP is comfirmed with molecular detection of UROS pathogenic variants or in hemizygous pathogenic X-linked gene GATA1 variant in rare occasions (Erwin, Balwani, & Desnick, 2016).

Treatment

There is no U.S. Food Drug and Drug Administration–approved treatment for CEP.  Bone marrow transplantation is the only cure for the disease. Blood transfusion can be used to manage the condition.  Preventive and protective strategies include avoidance of sunlight exposure and use of protective clothing, protective window films, wraparound sunglasses, reddish incandescent bulbs, opaque sunscreens containing titanium oxide or zinc oxide, and filtering screens for fluorescent lights (Erwin, Balwani, & Desnick, 2016). Secondary complications can be preventing through immunization of hepatitis A and B and vitamin D supplementation (Erwin, Balwani, & Desnick, 2016).

Possible Complications

            Possible conditions of the disease include transfusion-dependent hemolytic anemia, neonatal jaundice, splenomegaly, and thrombocytopenia (Erwin, Balwani, & Desnick, 2016).  Other complications include hyperpigmentation, corneal scarring, conjunctivitis, osteodystrophy, fragility of vertebrae and long bones, bone fractures, and polychromasia (Kahila et al., 2020).

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