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ORPHA:280133

Complement component 3 deficiency

low confidenceDisorder

Also known as: C3 deficiency

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

Publications

1,265

Trials

0

Interventional, condition-specific

Researchers

1,176

Distinct authors in sample

Gene link

C3

Definitive

Readiness

4/6

Stages with a signal

Clinical definition (Orphanet)

Complement component 3 deficiency is a rare, genetic, primary immunodeficiency characterized by susceptibility to infection (mainly by gram negative bacteria) due to extremely low C3 plasma levels. Patients typically present recurrent episodes of sinusitis, tonsillitis, and/or otitis, as well as upper and lower respiratory tract infections (including pneumonia) and skin infections, such as erythema multiforme. Autoimmune disease resembling systemic lupus erythematosus and mesangiocapillary or membranoproliferative glomerulonephritis may develop, resulting in renal failure.

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)

C3 classic complement early component deficiency · classic complement early component deficiency caused by mutation in C3

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 matched interventional trial, but a gene association and an animal model are on record — often described as translation-ready / stalled at the clinical step.

  1. Gene identifiedPresent

    Definitive — C3

  2. LiteraturePresent

    1,265 matched papers (710 in last 10 years) Source

  3. Phenotype characterisedPresent

    9 HPO annotations (e.g. Nephrotic syndrome; Membranoproliferative glomerulonephritis; Decreased circulating complement C3 concentration) Source

  4. Animal modelPresent

    3 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 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 (C3).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

9

Associated phenotypes · MONDO:0013417

  • Nephrotic syndrome
  • Membranoproliferative glomerulonephritis
  • Decreased circulating complement C3 concentration
  • Recurrent tonsillitis
  • Systemic lupus erythematosus

Showing 5 of 9 — open Monarch for the full list.

Animal models (Monarch / Alliance)

3

Model associations linked to this Mondo ID

Monarch fetch 2026-07-27

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?

1,265

1,265 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.

1,265 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).

710 in the last 10 years · low confidence

Phrase hits: 1,065 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,176

Distinct author names in 200 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
    Hwang DY8 papers · 2025

    Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, South Korea.

    Papers in Europe PMC
  2. 02
    Kim JE8 papers · 2025

    Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, South Korea.

    Papers in Europe PMC
  3. 03
    Li Y8 papers · 2026

    Department of Immunology, Nanjing Medical University, Nanjing, China.

    Papers in Europe PMC
  4. 04
    Yang Y8 papers · 2025

    From the Department of Integrative Medicine and Neurobiology, School of Basic Medical Science, Institutes of Integrative Medicine, Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Shanghai Medical College, Fudan University, Shanghai, China.

    Papers in Europe PMC
  5. 05
    Wang H6 papers · 2026

    Department of Day Surgery Center, The First Hospital of Lanzhou University, Lanzhou, Gansu, China.

    Papers in Europe PMC
  6. 06
    Wu X6 papers · 2026

    Department of Neurology, Minhang Hospital Fudan University Shanghai China.

    Papers in Europe PMC
  7. 07
    Atkinson JP5 papers · 2026

    Division of Rheumatology, Department of Medicine, Washington University School of Medicine, Saint Louis, Missouri, USA.

    Papers in Europe PMC
  8. 08
    Chen Y5 papers · 2023

    Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, China.

    Papers in Europe PMC
  9. 09
    Choi YJ5 papers · 2022

    Department of Biomaterials Science (BK21 FOUR Program), College of Natural Resources and Life Science/Life and Industry Convergence Research Institute, Pusan National University, Miryang, South Korea.

    Papers in Europe PMC
  10. 10
    Isaac L5 papers · 2025

    Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. Electronic address: louisaac@icb.usp.br.

    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 9 September 2026 · last trial check 9 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 6 · after dedupe 6 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 0 · dropped 6 · fetched 2026-07-27

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 Complement component 3 deficiency — 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.

("Complement component 3 deficiency" OR "C3 deficiency" OR "C3 classic complement early component deficiency" OR "classic complement early component deficiency caused by mutation in C3") OR (MESH:"Complement Component 3 Deficiency, Autosomal Recessive") OR ("C3 syndrome" OR "C3-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Complement Component 3 Deficiency, Autosomal Recessive

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

"Complement component 3 deficiency" OR "C3 deficiency" OR "C3 classic complement early component deficiency" OR "classic complement early component deficiency caused by mutation in C3" OR "Complement Component 3 Deficiency, Autosomal Recessive"

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

Query health: suspect — strategies attempted: phrase, mesh; 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 (1265) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-26T02:11:43.422Z