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ORPHA:2841

Hailey-Hailey disease

high confidenceDisorder

Also known as: Benign chronic familial pemphigus

Publications

3,662

89th percentile

Trials

4

Interventional, condition-specific

Researchers

898

Distinct authors in sample

Gene link

ATP2C1

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare, genetic, chronic epidermal disorder characterized by diffuse bilateral (or, rarely, localized segmental) erythematous plaques with blistering, erosions, maceration, and frequent secondary infection involving the flexural areas.

How rare: 1-9 / 100 000 — about one to nine people per hundred thousand.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (3)

benign chronic familial pemphigus of Hailey-Hailey · benign chronic pemphigus · pemphigus, benign familial

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.”

5/6 stages with a signal

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

  1. Gene identifiedPresent

    Definitive — ATP2C1

  2. LiteraturePresent

    3,662 matched papers (1,365 in last 10 years) Source

  3. Phenotype characterisedPresent

    6 HPO annotations (e.g. Erythema; Hyperkeratosis; Acantholysis) Source

  4. Animal modelNot found

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

  5. Orphan designationPresent

    1 FDA designation (1 FDA orphan-indication approval) — e.g. afamelanotide Source

  6. Interventional trialPresent

    4 matched on ClinicalTrials.gov (2 recruiting in sample)

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 (ATP2C1).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

6

Associated phenotypes · MONDO:0008218

  • Erythema
  • Hyperkeratosis
  • Acantholysis
  • Skin erosion

Showing 4 of 6 — open Monarch for the full list.

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)

1

Designation · 1 with FDA orphan-indication approval

  • FDA afamelanotideFamilial Benign Chronic Pemphigus · 2014-05-14 · Not FDA Approved for Orphan Indication

Sources: FDA OOPD · EMA orphan designations

Open Targets candidates

5

Drugs / clinical candidates · MONDO_0008218

CTD chemicals (MyDisease.info)

2 associated chemicals · 3 pathways. Therapeutic evidence is listed first when present — not a treatment recommendation.

  • Azathioprine · therapeutic
  • Vinblastine · therapeutic

Pathways: Transmembrane transport of small molecules; Ion transport by P-type ATPases; Ion channel transport

MyDisease.info · MONDO:0008218

Literature

Is anyone studying this?

3,662

3,662 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.

3,662 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).

1,365 in the last 10 years · high confidence · 89th percentile (publications denominator)

Phrase hits: 1,528 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

898

Distinct author names in 200 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
    Antoñanzas J5 papers · 2026

    Department of Dermatology, School of Medicine, University Clinic of Navarra, University of Navarra, Pamplona, Spain.

    Papers in Europe PMC
  2. 02
    Debeuf MPH5 papers · 2026

    Department of Dermatology, Centre of Expertise for Genodermatoses, Maastricht University Medical Centre+, Maastricht, the Netherlands.

    Papers in Europe PMC
  3. 03
    Salido-Vallejo R5 papers · 2026

    Department of Dermatology, School of Medicine, University Clinic of Navarra, University of Navarra, Pamplona, Spain.

    Papers in Europe PMC
  4. 04
    Steijlen PM5 papers · 2026

    Department of Dermatology, Centre of Expertise for Genodermatoses, Maastricht University Medical Centre+, Maastricht, the Netherlands.

    Papers in Europe PMC
  5. 05
    van Geel M5 papers · 2026

    Department of Dermatology, Centre of Expertise for Genodermatoses, Maastricht University Medical Centre+, Maastricht, the Netherlands.

    Papers in Europe PMC
  6. 06
    Verstraeten VLRM5 papers · 2026

    Department of Dermatology, Centre of Expertise for Genodermatoses, Maastricht University Medical Centre+, Maastricht, the Netherlands.

    Papers in Europe PMC
  7. 07
    España A4 papers · 2026

    Dermatology Department University Clinic of Navarra, Pamplona, Spain. Electronic address: aespana@unav.es.

    Papers in Europe PMC
  8. 08
    Mascaró JM Jr4 papers · 2026

    Dermatology Department, Hospital Clínic de Barcelona, Universidad de Barcelona, Barcelona, Spain. Electronic address: jmmascaro_galy@ub.edu.

    Papers in Europe PMC
  9. 09
    Argenziano G3 papers · 2026

    Dermatology Unit, Department of Mentals and Physical Health and Preventive Medicine, University of Campania Luigi Vanvitelli, Naples, Italy.

    Papers in Europe PMC
  10. 10
    Curman P3 papers · 2025

    Dermatology and Venereology Division, Department of Medicine (Solna), Karolinska Institutet, Stockholm, Sweden.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

4

interventional trials for this specific condition

4 interventional trials matched this specific condition name; 2 currently recruiting in our sample.

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

4 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 88.1th percentile).

high confidence · 88.1th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Observational and natural-history studies

2 observational studies match 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 0 · after dedupe 0 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 0 · fetched 2026-07-29

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).

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 Hailey-Hailey disease — 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.

("Hailey-Hailey disease" OR "Benign chronic familial pemphigus" OR "benign chronic familial pemphigus of Hailey-Hailey" OR "benign chronic familial pemphigus of the Hailey-Hailey" OR "benign chronic pemphigus" OR "pemphigus, benign familial") OR ("ATP2C1" OR "ATP2C1 syndrome" OR "ATP2C1-related")

Run this search on Europe PMC

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

"Hailey-Hailey disease" OR "Benign chronic familial pemphigus" OR "benign chronic familial pemphigus of Hailey-Hailey" OR "benign chronic familial pemphigus of the Hailey-Hailey" OR "benign chronic pemphigus" OR "pemphigus, benign familial"

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: 4 interventional · 2 observational · 0 expanded access. Only interventional studies enter the trial headline.

Query health: ok — strategies attempted: phrase; with hits: phrase

Run this search on ClinicalTrials.gov

Confidence reasoning

  • Preferred label is multi-word and distinctive
  • No synonyms dropped by stoplist
  • No label/synonym collisions with other diseases in this corpus

Ingested 2026-07-26T21:24:58.880Z