protoporphyria, erythropoietic, 1
An erythropoietic protoporphyria caused by biallelic variants in FECH (an autosomal recessive inheritance pattern) and causing primarily accumulation of protoporphyrin IX. Symptoms include extremely painful photosensitivity in childhood, possible microcytic anemia, cholelithiasis, and ~5% of patients develop liver failure. The majority of individuals with FECH-related erythropoietic protoporphyria harbor a hypomorphic variant (NM_000140.5:c.315-48T>C), which reduces enzyme levels by ~35%, in trans to a second pathogenic variant. Clinically individuals with this form of porphyria cannot be distinguished from those with ALAS2-related erythropoietic protoporphyria.