ORPHA:2698
Knuckle pads-leukonychia-sensorineural deafness-palmoplantar hyperkeratosis syndrome
Also known as: Bart-Pumphrey syndrome · Knuckle pads-leukonychia-sensorineural deafness-palmoplantar keratoderma syndrome · Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar hyperkeratosis syndrome · Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar keratoderma syndrome
Publications
7,557
Trials
0
Interventional, condition-specific
Researchers
544
Distinct authors in sample
Gene link
GJB2
Definitive
Readiness
3/6
Stages with a signal
Clinical definition (Orphanet)
A rare, syndromic genetic deafness disease characterized by symmetric or asymmetric knuckle pads (typically located on the distal and interphalangeal joints), leukonychia, diffuse palmoplantar keratoderma, and , mild to moderate sensorineural deafness.
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.
Cross-references
Joined from Mondo / Orphanet. MeSH labels may enter searches; UMLS / OMIM / NCIT are stored for reference.
- MONDO:0007866
- MeSH:C537210
- OMIM:149200
- UMLS:C0266004
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.”
3/6 stages with a signal
No matched interventional trial; the gene is known and literature exists — preclinical or natural-history work may still be the practical next step.
- Gene identifiedPresent
Definitive — GJB2
- LiteraturePresent
7,557 matched papers (4,011 in last 10 years) Source
- Phenotype characterisedPresent
11 HPO annotations (e.g. Leukonychia; Knuckle pad; Palmoplantar hyperkeratosis) Source
- Animal modelNot found
No Alliance genotype “model of” associations via Monarch for these Mondo IDs
- Orphan designationNot found
No FDA or EMA orphan-drug designation matched this disease via UMLS or preferred name Source
- Interventional trialNot found
No matched interventional trial under our ClinicalTrials.gov rules
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 (GJB2).
GenCC classification: Definitive.
Phenotypes (Monarch / HPO)
11
Associated phenotypes · MONDO:0007866
- Leukonychia
- Knuckle pad
- Palmoplantar hyperkeratosis
- Hyperkeratotic papule
- Congenital sensorineural hearing impairment
Showing 5 of 11 — 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)
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?
7,557
7,557 papers — among the better-studied rare conditions, though still a fraction of common-disease literature (breast cancer: over 700,000). Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.
7,557 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).
4,011 in the last 10 years · low confidence
Phrase hits: 100 · MeSH hits: 0
Who's working on it?
544
Distinct author names in 100 sampled papers — named people below.
Who's working on it?
No interventional trial matched this name; these authors publish on it in the sampled literature — a practical starting point for contact.
- 01White TW8 papers · 2019
Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York, USA. Electronic address: thomas.white@stonybrook.edu.
Papers in Europe PMC - 02Laird DW7 papers · 2023
Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada N6A 5C1. dale.laird@schulich.uwo.ca
Papers in Europe PMC - 03Shao Q5 papers · 2023
Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.
Papers in Europe PMC - 04Li L4 papers · 2023
BGI-Wuhan Clinical Laboratory, BGI-Shenzhen, 430074, Wuhan, China.
Papers in Europe PMC - 05Wang Y4 papers · 2024
Center for Medical Genetics, Gansu Provincial Maternity and Child Health Hospital, Gansu Provincial Clinical Research Center for Birth Defects and Rare Diseases, Lanzhou, China.
Papers in Europe PMC - 06Chen Y3 papers · 2023
Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute, Shanghai Jiaotong University, Shanghai, China.
Papers in Europe PMC - 07Liu Y3 papers · 2025
Department of Genetics, Jiangxi Maternal and Child Health Hospital, 330006, Nanchang, China.
Papers in Europe PMC - 08
- 09Bazazzadegan N2 papers · 2016
Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
Papers in Europe PMC - 10Daneshi A2 papers · 2016
Head and Neck Surgery Department and Research Center, Iran University of Medical Sciences, Tehran, Iran.
Papers in Europe PMC
Clinical research
Is a treatment being tested?
0
interventional trials for this specific condition
No interventional trial testing a treatment matched this specific condition name on ClinicalTrials.gov (observational studies and pan-disease registries are listed separately when present).
Data as of 11 September 2026 · last trial check 11 September 2026
No matched interventional trials. This is true for 77.2% of diseases in the trials denominator (5501 of 7126). Here are the researchers publishing on it.
low confidence · 38.6th percentile (trials denominator)
Recruiting interventional trials
From the matched ClinicalTrials.gov set
No interventional trial testing a treatment was found for this specific condition name on ClinicalTrials.gov.
See who's working on it — people publishing on this disease are often the practical next contact when no trial is listed.
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 Knuckle pads-leukonychia-sensorineural deafness-palmoplantar hyperkeratosis syndrome — check Associations / patient organisations on that page.
India — NPRD
Last verified 2026-07-26This 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.
("Knuckle pads-leukonychia-sensorineural deafness-palmoplantar hyperkeratosis syndrome" OR "Bart-Pumphrey syndrome" OR "Knuckle pads-leukonychia-sensorineural deafness-palmoplantar keratoderma syndrome" OR "Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar hyperkeratosis syndrome" OR "Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar keratoderma syndrome") OR ("GJB2" OR "GJB2 syndrome" OR "GJB2-related")ClinicalTrials.gov query (quoted phrases + MeSH via query.cond, plus recall-expansion terms when used):
"Knuckle pads-leukonychia-sensorineural deafness-palmoplantar hyperkeratosis syndrome" OR "Bart-Pumphrey syndrome" OR "Knuckle pads-leukonychia-sensorineural deafness-palmoplantar keratoderma syndrome" OR "Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar hyperkeratosis syndrome" OR "Knuckle pads-leukonychia-sensorineural hearing loss-palmoplantar keratoderma syndrome"
Study-type breakdown: 0 interventional · 0 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
- Publication count (7557) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity
Ingested 2026-07-26T20:53:09.920Z