X-linked disease erythropoietic protoporphyria X-linked erythropoietic protoporphyria https://github.com/monarch-initiative/mondo/issues/9703 https://www.malacards.org/card/protoporphyria_erythropoietic_x_linked ALAS2-related erythropoietic protoporphyria UMLS:C2677889 XLDPP XLP NANDO:2201269 OMIM:300752 GARD:0017755 An erythropoietic protoporphyria in which the cause of the disease is a hemizygous, heterozygous, or homozygous (rare) gain-of-function (GOF) variant (X-linked inheritance pattern) in the terminal regulatory exon of ALAS2. GOF variants increase ALAS2 activity resulting in pathway upregulation and high levels of protoporphyrin IX (PPIX). Males with hemizygous variants frequently present in early childhood with severe cutaneous photosensitivity and laboratory markers of liver disease. Heterozygous females can present with symptoms ranging from as severe as affected males to asymptomatic due to random X-chromosome inactivation. This disease is clinically indistinguishable from FECH-related erythropoietic protoporphyria. NANDO:1200818 XLEPP MESH:C567464 X-linked dominant protoporphyria X-linked dominant erythropoietic protoporphyria protoporphyria, erythropoietic, X-linked Orphanet:443197 MONDO:0010420 XLPP MEDGEN:394385 erythropoietic protoporphyria, X-linked