Two Novel FECH Mutations in a Patient with Erythropoietic Protoporphyria

Abstract

Introduction: Erythropoietic protoporphyria (EPP) is a rare photodermatosis mainly caused by deficiency of the enzyme ferrochelatase (FECH). We herein report a case of EPP associated with two novel mutations in 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 two 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 two novel mutations were likely pathogenic. Although the patient’s parents were healthy, they each had one of these two 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 two 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.