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ORPHA:443197

X-linked erythropoietic protoporphyria

low confidenceDisorder

Also known as: X-linked dominant erythropoietic protoporphyria · X-linked dominant protoporphyria · XLDPP · XLPP

Query health: suspect — Only one of 2 strategies returned hits (phrase).

Publications

2,616

Trials

2

Interventional, condition-specific

Researchers

856

Distinct authors in sample

Gene link

ALAS2

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare disorder of heme metabolism characterized by severe cutaneous photosensitivity in affected boys and sometimes in girls, manifesting in childhood.

How rare: <1 / 1 000 000 — fewer than one in a million. In a city the size of Kolkata, that might mean on the order of fifteen people.

Orphanet entry

Cross-references

Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.

Additional Mondo synonyms (2)

ALAS2-related erythropoietic protoporphyria · erythropoietic protoporphyria, X-linked

Research stages

Trial readiness signals

Where this condition sits on an open-data research pipeline — not how close a treatment is, and not medical advice. Empty stages often mean “not in these databases under this Mondo ID,” not “impossible.”

4/6 stages with a signal

An interventional trial matched this condition name on ClinicalTrials.gov — see trials below.

  1. Gene identifiedPresent

    Definitive — ALAS2

  2. LiteraturePresent

    2,616 matched papers (1,768 in last 10 years) Source

  3. Phenotype characterisedPresent

    5 HPO annotations (e.g. Iron deficiency anemia; Increased erythrocyte protoporphyrin concentration; Cutaneous photosensitivity) Source

  4. Animal modelNot found

    No Alliance genotype “model of” associations via Monarch for these Mondo IDs

  5. Orphan designationNot found

    No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source

  6. Interventional trialPresent

    2 matched on ClinicalTrials.gov

Biology

Genes and phenotypes

Gene–disease validity from GenCC, plus phenotypes and animal models joined from Monarch Initiative via Mondo ID — not a clinical diagnosis aid.

Do we know what causes it?

Yes — we know a specific gene responsible (ALAS2).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

5

Associated phenotypes · MONDO:0010420

  • Iron deficiency anemia
  • Increased erythrocyte protoporphyrin concentration
  • Cutaneous photosensitivity
  • Elevated circulating hepatic transaminase concentration
  • Cholelithiasis

Animal models (Monarch / Alliance)

None returned for this Mondo ID. Empty here is not proof that no model organism work exists under another name or gene.

Monarch fetch 2026-07-29

Therapies

Designations, candidates, and chemicals

FDA OOPD and EMA orphan designations, Open Targets clinical candidates, and CTD chemical associations via MyDisease.info. These never change the interventional-trial headline.

Orphan designation (FDA · EMA)

No designation matched this disease via UMLS or preferred name on the FDA OOPD mirror or EMA orphan register. Absence here is not proof that none exists under another wording.

Open Targets candidates

No drugs or clinical candidates returned for this Mondo ID on Open Targets.

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

2,616

2,616 papers have been published on this condition. That is a real research literature — still far smaller than common diseases (breast cancer: over 700,000 papers). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

2,616 papers since the earliest indexed year in this search — median last-10-year count for a rare disease in this dataset is 59 (publications denominator n=3967).

1,768 in the last 10 years · low confidence

Phrase hits: 188 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

856

Distinct author names in 188 sampled papers — named people below.

Who's working on it?

People publishing on this condition (sampled Europe PMC records). Affiliation is the most recent found in that sample.

  1. 01
    Anderson KE15 papers · 2026

    Department of Preventive Medicine and Community Health, The University of Texas Medical Branch, Galveston, Texas.

    Papers in Europe PMC
  2. 02
    Balwani M15 papers · 2025

    Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA.

    Papers in Europe PMC
  3. 03
    Puy H15 papers · 2022

    Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier , 178 rue des Renouillers, 92701 Colombes Cedex, France.

    Papers in Europe PMC
  4. 04
    Desnick RJ14 papers · 2022

    Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, United States. Electronic address: Robert.Desnick@mssm.edu.

    Papers in Europe PMC
  5. 05
    Gouya L14 papers · 2022

    Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier , 178 rue des Renouillers, 92701 Colombes Cedex, France.

    Papers in Europe PMC
  6. 06
    Naik H13 papers · 2025

    Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, New York.

    Papers in Europe PMC
  7. 07
    Ferreira GC12 papers · 2025

    Department of Molecular Medicine, Morsani College of Medicine, University of South Florida , Tampa, Florida 33612, United States.

    Papers in Europe PMC
  8. 08
    Bonkovsky HL11 papers · 2025

    Department of Internal Medicine, Section on Gastroenterology.

    Papers in Europe PMC
  9. 09
    Deybach JC11 papers · 2015

    Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier , 178 rue des Renouillers, 92701 Colombes Cedex, France.

    Papers in Europe PMC
  10. 10
    Ducamp S8 papers · 2025

    Assistance Publique-Hôpitaux de Paris, Centre Français des Porphyries, Hôpital Louis Mourier , 178 rue des Renouillers, 92701 Colombes Cedex, France.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

2

interventional trials for this specific condition

2 interventional trials matched this specific condition name; none in our sample are currently recruiting. 21 trials are registered for erythropoietic protoporphyria, the broader category — shown separately because they may or may not enrol this specific subtype.

Data as of 11 September 2026 · last trial check 28 July 2026

2 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 84.5th percentile).

low confidence · 84.5th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

2 interventional trials matched after quoted-phrase search and title/condition post-filter.

No currently recruiting studies in the matched set. Open the same search on ClinicalTrials.gov.

Broader category: erythropoietic protoporphyria

21

Interventional trials for the parent category, exclusive of NCT IDs already counted above. Eligibility for this subtype is not guaranteed.

Worth raising with a clinician. How we count trials.

Recruiting under the broader category

Observational and natural-history studies

1 observational study matches this condition. These do not test a treatment and are not counted in the interventional-trial headline, but they are genuine research: natural-history work often defines the endpoints needed for a future rare-disease trial, and families may be able to enroll.

None of the matched observational studies is currently listed as recruiting.

Open the complete matched search on ClinicalTrials.gov

Other registries (secondary)

Broader net from EU CTIS, ISRCTN, and ICTRP when available — deduped against ClinicalTrials.gov IDs already counted above. Dual-model LLM relevance gates what we keep. These rows are not added to the interventional headline.

raw 1 · after dedupe 1 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 1 · dropped 0 · fetched 2026-07-30

Source notes: ictrp: Error: ICTRP public search unavailable (WHO portal is SPA-only; SOAP needs partnership). Tried: https://apps.who.int/tri

No secondary-registry studies passed dual-model relevance for this condition name (after dedupe).

Uncertain / not reviewed (1)

Where to find support

Condition-specific patient organisations, when Orphanet lists them, are on the disease’s Orphanet page. We also link umbrella groups that support undiagnosed and ultra-rare families.

Orphanet entry for X-linked erythropoietic protoporphyria — check Associations / patient organisations on that page.

India — NPRD

Last verified 2026-07-26

This ORPHAcode is not on our curated NPRD list (direct or Mondo-parent match). That does not decide clinical eligibility; families in India should ask a notified Centre of Excellence about current coverage.

Hand-curated for this project. ORPHAcode mappings are best-effort and may be incomplete or imprecise for umbrella categories. Parent (Mondo) matches mean the policy lists a broader category — confirm eligibility with a Centre of Excellence. Financial entitlements summarised from public policy statements and may change. This is not official government guidance.

How we counted this

Europe PMC query (preferred label + any corrected label + Orphanet and Mondo exact synonyms, stoplisted; unioned with resolved MeSH labels when available). UMLS / OMIM / NCIT cross-references are stored on the overview but are not added to the query string.

("X-linked erythropoietic protoporphyria" OR "X-linked dominant erythropoietic protoporphyria" OR "X-linked dominant protoporphyria" OR "XLDPP" OR "ALAS2-related erythropoietic protoporphyria" OR "erythropoietic protoporphyria, X-linked") OR (MESH:"Protoporphyria, Erythropoietic, X-Linked Dominant") OR ("ALAS2" OR "ALAS2 syndrome" OR "ALAS2-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Protoporphyria, Erythropoietic, X-Linked Dominant

ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):

"X-linked erythropoietic protoporphyria" OR "X-linked dominant erythropoietic protoporphyria" OR "X-linked dominant protoporphyria" OR "XLDPP" OR "ALAS2-related erythropoietic protoporphyria" OR "erythropoietic protoporphyria, X-linked" OR "Protoporphyria, Erythropoietic, X-Linked Dominant"

Interventional trials matched via: phrase (mesh = registered under a MeSH descriptor no name phrase would catch; recall-expansion = gene / selected parent terms used only for trials).

Study-type breakdown: 2 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"erythropoietic protoporphyria"

Query health: suspect — strategies attempted: phrase, mesh; with hits: phrase

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: XLPP

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • 1 synonym(s) dropped by stoplist (may under-count)
  • No label/synonym collisions with other diseases in this corpus
  • Publication count (2616) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T16:26:09.465Z