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ORPHA:98973

Posterior polymorphous corneal dystrophy

low confidenceDisorder

Also known as: PPCD · Posterior polymorphous dystrophy · Schlichting dystrophy

Publications

2,555

Trials

2

Interventional, condition-specific

Researchers

1,013

Distinct authors in sample

Gene link

GRHL2

Strong

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

A rare mild subtype of posterior corneal characterized by small aggregates of apparent vesicles bordered by a gray haze at the level of Descemet membrane, generally with no effect on vision.

How rare: How common this is has not been clearly measured.

Orphanet entry

Cross-references

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

Additional Mondo synonyms (2)

corneal dystrophy, posterior polymorphous · posterior polymorphous dystrophy

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

    Strong — GRHL2

  2. LiteraturePresent

    2,555 matched papers (1,868 in last 10 years) Source

  3. Phenotype characterisedPresent

    43 HPO annotations (e.g. Abnormal Descemet membrane morphology; Reduced number of corneal endothelial cells; Astigmatism) 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 (GRHL2).

GenCC classification: Strong.

Phenotypes (Monarch / HPO)

43

Associated phenotypes · MONDO:0020364

  • Abnormal Descemet membrane morphology
  • Reduced number of corneal endothelial cells
  • Astigmatism
  • Glaucoma
  • Esotropia

Showing 5 of 43 — 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?

2,555

2,555 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.

2,555 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).

1,868 in the last 10 years · low confidence

Phrase hits: 725 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,013

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
    Liskova P11 papers · 2025

    Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic.

    Papers in Europe PMC
  2. 02
    Dudakova L10 papers · 2025

    Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic.

    Papers in Europe PMC
  3. 03
    Davidson AE9 papers · 2024

    UCL Institute of Ophthalmology, London EC1V 9EL, UK.

    Papers in Europe PMC
  4. 04
    Aldave AJ8 papers · 2021

    Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA.

    Papers in Europe PMC
  5. 05
    Skalicka P8 papers · 2025

    Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic.

    Papers in Europe PMC
  6. 06
    Chaurasia S7 papers · 2026

    Tej Kohli Cornea Institute, LV Prasad Eye Institute, Kallam Anji Reddy Campus, Banjara Hills, Hyderabad, 560 034, India. sunita@lvpei.org.

    Papers in Europe PMC
  7. 07
    Chung DD7 papers · 2021

    Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA.

    Papers in Europe PMC
  8. 08
    Frausto RF6 papers · 2021

    Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA.

    Papers in Europe PMC
  9. 09
    Gurnani B5 papers · 2026

    Cataract, Cornea and Refractive Services, Aravind Eye Hospital, Pondicherry, India.

    Papers in Europe PMC
  10. 10
    Hong J5 papers · 2026

    Department of Ophthalmology, Peking University Third Hospital, Beijing, China

    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. 34 trials are registered for corneal dystrophy, 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: corneal dystrophy

34

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 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 Posterior polymorphous corneal dystrophy — 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.

("Posterior polymorphous corneal dystrophy" OR "Posterior polymorphous dystrophy" OR "Schlichting dystrophy" OR "corneal dystrophy, posterior polymorphous") OR ("GRHL2" OR "GRHL2 syndrome" OR "GRHL2-related")

Run this search on Europe PMC

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

"Posterior polymorphous corneal dystrophy" OR "Posterior polymorphous dystrophy" OR "Schlichting dystrophy" OR "corneal dystrophy, posterior polymorphous"

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:

"corneal dystrophy"

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

Run this search on ClinicalTrials.gov

Synonyms dropped by stoplist: PPCD

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 (2555) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-27T05:49:39.504Z