X-linked dominant erythropoietic protoporphyria with early-onset manifestations caused by a hemizygous ALAS2 variant

Erythropoietic protoporphyria (EPP) is usually caused by autosomal dominant mutations FECH, blocking the conversion of protoporphyrin to haem. The resulting accumulation of protoporphyrin causes itching, burning and erythema after sun exposure, with facial scarring and, sometimes, liver damage. We report a 4-year-old boy from India with XLDPP with a previously unreported manifestation of photo-onycholysis and an unusually severe phenotype, possibly attributable to extensive sun exposure.