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ORPHA:157801

Mesoaxial synostotic syndactyly with phalangeal reduction

medium confidenceDisorder

Also known as: MSSD · Syndactyly type 9 · Syndactyly, Malik-Percin type

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

Publications

153

60.1th percentile

Trials

0

Interventional, condition-specific

Researchers

161

Distinct authors in sample

Gene link

BHLHA9

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare non-syndromic syndactyly characterized by mesoaxial reduction of fingers, complete syndactyly of the 3rd and 4th fingers with synostoses of the corresponding metacarpals and associated single phalanges, malformed thumbs, and hypoplasia and clinodactyly of the 5th finger. Preaxial webbing of toes with terminal phalangeal hypoplasia of all toes has been reported in association.

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)

syndactyly type 9 · syndactyly, Malik-Percin type

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

No specific-condition interventional trial, but broader-category trials exist — discuss eligibility with a clinician.

  1. Gene identifiedPresent

    Definitive — BHLHA9

  2. LiteraturePresent

    153 matched papers (124 in last 10 years) Source

  3. Phenotype characterisedPresent

    21 HPO annotations (e.g. Toe syndactyly; Clinodactyly of the 5th finger; Short palm) 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 trialPartial

    None under the specific name; 5 for broader category syndactyly

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 (BHLHA9).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

21

Associated phenotypes · MONDO:0012271

  • Toe syndactyly
  • Clinodactyly of the 5th finger
  • Short palm
  • Short hallux
  • Finger symphalangism

Showing 5 of 21 — 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?

153

153 papers have ever been published on this condition (under this name). For scale, breast cancer has over 700,000. Median papers in the last 10 years for a rare disease in this dataset (publications denominator n=3967) is 59.

153 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).

124 in the last 10 years · medium confidence · 60.1th percentile (publications denominator)

Phrase hits: 24 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

161

Distinct author names in 24 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.

  1. 01
    Ahmad W3 papers · 2019

    Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.

    Papers in Europe PMC
  2. 02
    Malik S3 papers · 2018

    Zentrum für Humangenetik, Philipps-Universität Marburg, Bahnhofstr. 7, Marburg, Germany. malik@staff.uni-marburg.de

    Papers in Europe PMC
  3. 03
    Akarsu NA2 papers · 2014

    Department of Medical Genetics, Gene Mapping Laboratory, Hacettepe University Medical Faculty, Sihhiye, 06100 Ankara, Turkey.

    Papers in Europe PMC
  4. 04
    Bertola DR2 papers · 2023

    Unidade de Genética, Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.

    Papers in Europe PMC
  5. 05
    Cormier-Daire V2 papers · 2023

    Paris Cité University, Reference Center for Skeletal Dysplasia, INSERM UMR 1163, Imagine Institute, Necker Enfants Malades Hospital (AP-HP), Paris, France.

    Papers in Europe PMC
  6. 06
    Dissanayake VHW2 papers · 2022

    Human Genetics Unit, Faculty of Medicine, University of Colombo, Kynsey Road, Colombo, 00800, Sri Lanka.

    Papers in Europe PMC
  7. 07
    Grzeschik KH2 papers · 2014

    Zentrum fuer Humangenetik, Philipps-Universitaet Marburg, 35033 Marburg, Germany. Electronic address: grzeschi@staff.uni-marburg.de.

    Papers in Europe PMC
  8. 08
    Hall C2 papers · 2023

    Emerita Consultant Paediatric Radiologist at Great Ormond Street Childrens' Hospital, London, UK.

    Papers in Europe PMC
  9. 09
    Koch MC2 papers · 2014

    Zentrum fuer Humangenetik, Philipps-Universitaet Marburg, 35033 Marburg, Germany.

    Papers in Europe PMC
  10. 10
    Krakow D2 papers · 2023

    Departments of Obstetrics and Gynecology, Orthopaedic Surgery and Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA.

    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). 5 trials are registered for syndactyly, the broader category — shown separately because they may or may not enrol this specific subtype.

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.

medium 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.

5 interventional trials matched syndactyly, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: syndactyly

5

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 2026-07-30

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).

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 Mesoaxial synostotic syndactyly with phalangeal reduction — 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.

("Mesoaxial synostotic syndactyly with phalangeal reduction" OR "Syndactyly type 9" OR "Syndactyly, Malik-Percin type") OR (MESH:"Syndactyly, Mesoaxial Synostotic, with Phalangeal Reduction") OR ("BHLHA9" OR "BHLHA9 syndrome" OR "BHLHA9-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Syndactyly, Mesoaxial Synostotic, with Phalangeal Reduction

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

"Mesoaxial synostotic syndactyly with phalangeal reduction" OR "Syndactyly type 9" OR "Syndactyly, Malik-Percin type" OR "Syndactyly, Mesoaxial Synostotic, with Phalangeal Reduction"

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

Parent-category trials query:

"syndactyly"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: MSSD

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 2026-07-27T07:59:44.255Z