RARE DISEASERESEARCH ATLAS
Open navigation menu

ORPHA:682

Hyperkalemic periodic paralysis

medium confidenceDisorder

Also known as: Adynamia episodica hereditaria · Familial hyperPP · Familial hyperkalemic periodic paralysis · Gamstorp disease · Gamstorp episodic adynamy · HYPP · HyperKPP · HyperPP · Hyperkalemic PP · Primary hyperPP · Primary hyperkalemic periodic paralysis

Publications

2,724

89.1th percentile

Trials

3

Interventional, condition-specific

Researchers

956

Distinct authors in sample

Gene link

SCN4A

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare muscle disorder characterized by episodic attacks of muscle weakness associated with an increase in serum potassium concentration.

How rare: 1-9 / 1 000 000 — roughly one to nine people per million. In a city the size of Kolkata, perhaps a few dozen.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (13)

adynamia episodica hereditaria · adynamia episodica hereditaria with or without myotonia · familial hyperPP · familial hyperkalemic periodic paralysis · familial hyperkalemic periodic paralysis (disorder) [ambiguous] · hyperKPP · hyperPP · hyperkalemic PP · hyperkalemic periodic paralysis · hyperkalemic periodic paralysis, type 2 · normokalemic periodic paralysis, potassium-sensitive · primary hyperPP · primary hyperkalemic periodic paralysis

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 — SCN4A

  2. LiteraturePresent

    2,724 matched papers (1,377 in last 10 years) Source

  3. Phenotype characterisedPresent

    33 HPO annotations (e.g. Myotonia; Periodic hyperkalemic paralysis; Arrhythmia) Source

  4. Animal modelPresent

    4 genotype models (Mus musculus) Source

  5. Orphan designationNot found

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

  6. Interventional trialPresent

    3 matched on ClinicalTrials.gov (1 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 (SCN4A).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

33

Associated phenotypes · MONDO:0008224

  • Myotonia
  • Periodic hyperkalemic paralysis
  • Arrhythmia
  • Ophthalmoparesis
  • Congestive heart failure

Showing 5 of 33 — open Monarch for the full list.

Animal models (Monarch / Alliance)

4

Model associations linked to this Mondo ID

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

1

Drugs / clinical candidates · MONDO_0008224

CTD chemicals (MyDisease.info)

No CTD chemical associations returned for this Mondo ID.

Literature

Is anyone studying this?

2,724

2,724 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.

2,724 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).

1,377 in the last 10 years · medium confidence · 89.1th percentile (publications denominator)

Phrase hits: 1,028 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

956

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
    Hanna MG13 papers · 2025

    MRC Centre for Neuromuscular Diseases, Department of Neuromuscular diseases, UCL Queen Square Institute of Neurology, United Kingdom.

    Papers in Europe PMC
  2. 02
    Cannon SC8 papers · 2025

    Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California.

    Papers in Europe PMC
  3. 03
    Finno CJ7 papers · 2026

    Department of Population Health and Reproduction, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.

    Papers in Europe PMC
  4. 04
    Jurkat-Rott K7 papers · 2017

    Division of Neurophysiology, University of Ulm, 89069 Ulm, Germany.

    Papers in Europe PMC
  5. 05
    Matthews E7 papers · 2023

    MRC Centre for Neuromuscular Diseases, Department of Neuromuscular diseases, UCL Queen Square Institute of Neurology, United Kingdom.

    Papers in Europe PMC
  6. 06
    Kubota T6 papers · 2026

    Department of Neurology, Osaka University Graduate School of Medicine, Osaka, Japan.

    Papers in Europe PMC
  7. 07
    Lehmann-Horn F6 papers · 2017

    Division of Neurophysiology, Ulm University, Germany.

    Papers in Europe PMC
  8. 08
    Vivekanandam V6 papers · 2024

    MRC Centre for Neuromuscular Diseases (KJS, VV, NJ, SH, DF, MGH, ELM), Queen Square Institute of Neurology, UCL and National Hospital for Neurology and Neurosurgery; and Neurogenetics Unit (RS), National Hospital for Neurology and Neurosurgery, Queen Square, London, UK.

    Papers in Europe PMC
  9. 09
    Bellone RR5 papers · 2026

    Department of Population Health and Reproduction, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California Davis, Davis, California, USA.

    Papers in Europe PMC
  10. 10
    Hayward LJ5 papers · 2020

    Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01655.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

3

interventional trials for this specific condition

3 interventional trials matched this specific condition name; 1 currently recruiting in our sample. 2 trials are registered for periodic paralysis, 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

3 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 86.7th percentile).

medium confidence · 86.7th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

Broader category: periodic paralysis

2

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.

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 Hyperkalemic periodic paralysis — 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.

("Hyperkalemic periodic paralysis" OR "Adynamia episodica hereditaria" OR "Familial hyperPP" OR "Familial hyperkalemic periodic paralysis" OR "Gamstorp disease" OR "Gamstorp episodic adynamy" OR "HyperKPP" OR "HyperPP" OR "Hyperkalemic PP" OR "Primary hyperPP" OR "Primary hyperkalemic periodic paralysis" OR "adynamia episodica hereditaria with or without myotonia" OR "familial hyperkalemic periodic paralysis (disorder) [ambiguous]" OR "hyperkalemic periodic paralysis, type 2" OR "normokalemic periodic paralysis, potassium-sensitive") OR ("SCN4A" OR "SCN4A syndrome" OR "SCN4A-related")

Run this search on Europe PMC

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

"Hyperkalemic periodic paralysis" OR "Adynamia episodica hereditaria" OR "Familial hyperPP" OR "Familial hyperkalemic periodic paralysis" OR "Gamstorp disease" OR "Gamstorp episodic adynamy" OR "HyperKPP" OR "HyperPP" OR "Hyperkalemic PP" OR "Primary hyperPP" OR "Primary hyperkalemic periodic paralysis" OR "adynamia episodica hereditaria with or without myotonia" OR "familial hyperkalemic periodic paralysis (disorder) [ambiguous]" OR "hyperkalemic periodic paralysis, type 2" OR "normokalemic periodic paralysis, potassium-sensitive"

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

Parent-category trials query:

"periodic paralysis"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: HYPP

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

Ingested 2026-07-26T14:55:36.347Z