Case of late‐onset erythropoietic protoporphyria with myelodysplastic syndrome who has homozygous IVS 3‐48C polymorphism in the ferrochelatase gene

We report the case of a 42‐year‐old man with a 5‐year history of myelodysplastic syndrome and photosensitivity who had developed painful erythema and blisters on sun‐exposed sites. Histological examination of a mildly lichenified lesion on the dorsal finger revealed extensive deposits of a hyaline‐like, periodic acid‐Schiff‐positive material around superficial dermal blood vessels. Laboratory tests showed elevated erythrocyte protoporphyrin and normal urinary porphyrins, suggesting a diagnosis of erythropoietic protoporphyria. Late‐onset erythropoietic protoporphyria is rare and is usually associated with an acquired somatic mutation of the ferrochelatase gene secondary to a hematological malignancy such as myelodysplastic syndrome. DNA analysis revealed that our patient has the homozygous IVS 3‐48C polymorphism that is a low‐expression variant of wild‐type ferrochelatase allele.