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ORPHA:41751

Bietti crystalline dystrophy

medium confidenceDisorder

Also known as: BCD · Bietti crystalline corneoretinal dystrophy · Bietti crystalline retinopathy

Publications

942

85.7th percentile

Trials

9

Interventional, condition-specific

Researchers

999

Distinct authors in sample

Gene link

CYP4V2

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

A rare tapetoretinal degeneration disease, occurring in the third decade of life, characterized by small sparkling crystalline deposits in the posterior retina and corneal limbus in addition to sclerosis of the choroidal vessels and manifesting as nightblindness, decreased vision, paracentral scotoma, and, in the end stages of the disease, legal blindness.

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.

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 — CYP4V2

  2. LiteraturePresent

    942 matched papers (694 in last 10 years) Source

  3. Phenotype characterisedPresent

    29 HPO annotations (e.g. High myopia; Constriction of peripheral visual field; Paracentral scotoma) Source

  4. Animal modelPresent

    2 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

    9 matched on ClinicalTrials.gov (3 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 (CYP4V2).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

29

Associated phenotypes · MONDO:0008865

  • High myopia
  • Constriction of peripheral visual field
  • Paracentral scotoma
  • Retinal degeneration
  • Reduced visual acuity

Showing 5 of 29 — open Monarch for the full list.

Animal models (Monarch / Alliance)

2

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

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?

942

942 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.

942 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).

694 in the last 10 years · medium confidence · 85.7th percentile (publications denominator)

Phrase hits: 356 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

999

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
    Li Y13 papers · 2026

    Tongren Eye Center, Beijing key Laboratory of Intraocular Tumor Diagnosis and Treatment, Beijing Ophthalmology&Visual Sciences Key Lab, Medical Artificial Intelligence Research and Verification Key Laboratory of the Ministry of Industry and Information Technology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.

    Papers in Europe PMC
  2. 02
    Liu Y12 papers · 2026

    The Physical Examination Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, Henan, China.

    Papers in Europe PMC
  3. 03
    Wang J12 papers · 2026

    Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100730, China.

    Papers in Europe PMC
  4. 04
    Li H11 papers · 2026

    Department of Ophthalmology, Peking Union Medical College Hospital, Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.

    Papers in Europe PMC
  5. 05
    Yang L10 papers · 2026

    Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China. alexlipingyang@bjmu.edu.cn.

    Papers in Europe PMC
  6. 06
    Liu X9 papers · 2026

    Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China.

    Papers in Europe PMC
  7. 07
    Wang L9 papers · 2026

    Hebei Provincial Key Laboratory of Ophthalmology, Hebei Provincial Eye Institute, Hebei Provincial Eye Hospital, 399 East Quanbei Street, Xingtai, 054001, Hebei, People's Republic of China.

    Papers in Europe PMC
  8. 08
    Yu S9 papers · 2026

    Department of Ophthalmology, Peking University Third Hospital, Beijing, 100191, China.

    Papers in Europe PMC
  9. 09
    Zhang H9 papers · 2026

    Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China.

    Papers in Europe PMC
  10. 10
    Li Q8 papers · 2026

    Department of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing, China.

    Papers in Europe PMC

Clinical research

Is a treatment being tested?

9

interventional trials for this specific condition

9 interventional trials matched this specific condition name; 3 currently recruiting in our sample.

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

9 interventional trials — more than 77.2% of diseases in the trials denominator have none at all (5501 of 7126; this disease is at the 92th percentile).

medium confidence · 92th percentile (trials denominator)

Recruiting interventional trials

From the matched ClinicalTrials.gov set

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

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 Bietti crystalline 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.

("Bietti crystalline dystrophy" OR "Bietti crystalline corneoretinal dystrophy" OR "Bietti crystalline retinopathy") OR ("CYP4V2" OR "CYP4V2 syndrome" OR "CYP4V2-related")

Run this search on Europe PMC

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

"Bietti crystalline dystrophy" OR "Bietti crystalline corneoretinal dystrophy" OR "Bietti crystalline retinopathy"

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: 9 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

Synonyms dropped by stoplist: BCD

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 2026-07-27T00:04:22.953Z