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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Heartburn drug could ease painful sun sensitivity
Disease control CompletedThis Phase 2 trial tested whether oral cimetidine (Tagamet), a common heartburn drug, can reduce light sensitivity in people with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLP). These genetic conditions cause severe pain from sunlight exposure. The study en…
Phase 2 • Sponsor: Amy K. Dickey, M.D. • Aim: Disease control
Last updated Sep 06, 2026 00:00 UTC
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New drug aims to let sunlight-sensitive patients enjoy the sun longer
Symptom relief CompletedThis study tested a drug called MT-7117 in 165 adults and adolescents (ages 12-75) with erythropoietic protoporphyria (EPP) or X-linked protoporphyria (XLP), conditions that cause severe pain from sunlight exposure. The goal was to see if the drug could delay the first symptoms o…
Phase 3 • Sponsor: Tanabe Pharma America, Inc. • Aim: Symptom relief
Last updated Jun 27, 2026 13:02 UTC
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New drug may let people with rare sun allergy enjoy the outdoors longer
Symptom relief CompletedThis study tested a drug called MT-7117 in 184 people aged 12 to 75 with erythropoietic protoporphyria (EPP) or X-linked protoporphyria (XLP), rare conditions that cause severe pain from sunlight. The goal was to see if the drug could delay the first signs of sun sensitivity (bur…
Phase 3 • Sponsor: Tanabe Pharma America, Inc. • Aim: Symptom relief
Last updated Jun 27, 2026 08:07 UTC