摘要Introduction::Erythropoietic protoporphyria (EPP) is a rare photodermatosis mainly caused by deficiency of the enzyme ferrochelatase (FECH).Case presentation::A 15-year-old boy experienced pain and pruritus after sunlight exposure. He had occasional claret-red urine, hepatomegaly with increased alanine aminotransferase and aspartate aminotransferase levels, and an elevated free erythrocyte protoporphyrin level. He was treated with oral β-carotene and cholestyramine and avoidance of sunlight as much as possible.Discussion::Genome sequencing revealed 2 novel FECH mutations that had been inherited from his healthy parents. Pathogenicity analysis involving prediction using PolyPhen-2, SIFT, and Mutation Taster revealed that the 2 novel mutations were likely pathogenic. Although the patient’s parents were healthy, they each had one of these 2 mutations. This finding is consistent with previous reports stating that individuals carrying low-expression alleles can be asymptomatic. The pathogenesis of the disease caused by these 2 mutations requires verification by larger and more detailed studies. Conclusion::Although the precise role of these mutations in EPP is not clear, the findings in the present case expand the genotypic spectrum of the disease.

abstractsIntroduction::Erythropoietic protoporphyria (EPP) is a rare photodermatosis mainly caused by deficiency of the enzyme ferrochelatase (FECH).Case presentation::A 15-year-old boy experienced pain and pruritus after sunlight exposure. He had occasional claret-red urine, hepatomegaly with increased alanine aminotransferase and aspartate aminotransferase levels, and an elevated free erythrocyte protoporphyrin level. He was treated with oral β-carotene and cholestyramine and avoidance of sunlight as much as possible.Discussion::Genome sequencing revealed 2 novel FECH mutations that had been inherited from his healthy parents. Pathogenicity analysis involving prediction using PolyPhen-2, SIFT, and Mutation Taster revealed that the 2 novel mutations were likely pathogenic. Although the patient’s parents were healthy, they each had one of these 2 mutations. This finding is consistent with previous reports stating that individuals carrying low-expression alleles can be asymptomatic. The pathogenesis of the disease caused by these 2 mutations requires verification by larger and more detailed studies. Conclusion::Although the precise role of these mutations in EPP is not clear, the findings in the present case expand the genotypic spectrum of the disease.