Abstract
Erythopoietic protoporphyria (EPP) is an incomplete autosomal dominant disorder caused by an accumulation of protoporphyrin IX (PpIX) due to an impaired activity of ferrochelatase (FECH) in the heme synthetic pathway. EPP is often found in association with photosensitivity. Blood tests including an erythrocyte photohemolysis test (EPT) and an erythrocyte fluorescence test (EFT) were performed on a 10-year-old male with photosensitivity. In the patient’s erythrocytes, we observed hemolysis induced by sunlight in EPT and autofluorescence in EFT. Porphyrin analysis showed an increased level of protoporphyrin in erythrocytes, whereas the levels of other porphyrins were within normal limits. Hence, he was diagnosed as having EPP. Genetic analysis was performed and a point mutation was found in exon 6 of the FECH gene (c.683C>T, p.Pro228Leu) in heterozygotes, and a genetic polymorphism IVS3-48C was also identified on the contralateral side of the mutant allele. Taken together, we believe that in-house EPT and EFT should be performed, which could contribute to the early diagnosis of EPP.
