X-linked erythropoietic protoporphyria
MONDO:0010420An 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.
Also known as: ALAS2-related erythropoietic protoporphyria, X-linked dominant erythropoietic protoporphyria, X-linked dominant protoporphyria, XLDPP, XLPP, erythropoietic protoporphyria, X-linked, Erythrohepatic protoporphyria, X-linked, XLEPP
11 clinical trials for this condition and its sub-types, 10 tagged with X-linked erythropoietic protoporphyria itself.
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A pill that could let people with rare sunlight disorder step outside without pain
Disease control Recruiting nowResearchers are testing an oral drug called PORT-77 in people with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP), rare conditions that cause severe pain after sunlight exposure. The trial enrolls about 225 adults and adolescents aged 12 and older. It compa…
Phase 2/3 • Sponsor: Portal Therapeutics, Inc. • Aim: Disease control
Last updated Sep 17, 2026 00:00 UTC
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New hope for rare sun allergy: bitopertin offered to patients with no options
Disease control Expanded accessThis expanded access program provides bitopertin (DISC-1459) to patients aged 12 and older with erythropoietic protoporphyria (EPP) or X-linked protoporphyria (XLP) who have no satisfactory treatment options in the US. The goal is to offer access and gather safety information. Pa…
Sponsor: Disc Medicine, Inc • Aim: Disease control
Last updated Aug 05, 2026 00:00 UTC
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New study aims to unlock mysteries of rare sun allergy disorders
Knowledge-focused Recruiting nowThis observational study is gathering information on how erythropoietic protoporphyria (EPP) and X-linked porphyria (XLP) affect people aged 12 and older. Over 6 months, researchers will track symptoms, light exposure, and blood levels of protoporphyrin IX (PPIX) in 50 participan…
Sponsor: Portal Therapeutics, Inc. • Aim: Knowledge-focused
Last updated Jun 27, 2026 12:29 UTC