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ORPHA:101089

Hyper-IgM syndrome type 2

low confidenceSubtype of disorder

Also known as: AID deficiency · Activation-induced cytidine deaminase deficiency · HIGM2

Publications

3,746

Trials

0

Interventional, condition-specific

Researchers

1,283

Distinct authors in sample

Gene link

AICDA

Definitive

Readiness

5/6

Stages with a signal

Orphanet entry

Cross-references

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

Additional Mondo synonyms (5)

AICDA hyper-IgM syndrome · activation-induced cytidine deaminase deficiency · aid deficiency · hyper-IgM syndrome caused by mutation in AICDA · hyper-IgM syndrome type 2

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

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

  1. Gene identifiedPresent

    Definitive — AICDA

  2. LiteraturePresent

    3,746 matched papers (2,026 in last 10 years) Source

  3. Phenotype characterisedPresent

    11 HPO annotations (e.g. Recurrent bacterial infections; Lymphadenopathy; Recurrent respiratory infections) Source

  4. Animal modelPresent

    1 genotype model (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 trialPartial

    None under the specific name; 5 for broader category hyper-IgM syndrome

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 (AICDA).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

11

Associated phenotypes · MONDO:0011528

  • Recurrent bacterial infections
  • Lymphadenopathy
  • Recurrent respiratory infections
  • Decreased circulating IgA concentration
  • Immunodeficiency

Showing 5 of 11 — open Monarch for the full list.

Animal models (Monarch / Alliance)

1

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?

3,746

3,746 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.

3,746 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).

2,026 in the last 10 years · low confidence

Phrase hits: 360 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

1,283

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
    Durandy A20 papers · 2021

    INSERM, U768, Paris 75015, France. anne.durandy@inserm.fr

    Papers in Europe PMC
  2. 02
    Kracker S9 papers · 2024

    INSERM, U768; Université Paris Descartes, Faculté de Médecine René Descartes, Paris, F-75005, France.

    Papers in Europe PMC
  3. 03
    Honjo T8 papers · 2017

    Department of Immunology and Genomic Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.

    Papers in Europe PMC
  4. 04
    Fischer A7 papers · 2021

    Institut National de la Santé et de la Recherche Médicale (INSERM) Unité Mixte de Recherche (UMR) 1163, Laboratory of Human Lympho-hematopoiesis, Imagine Institute, Université de Paris, Paris, France.

    Papers in Europe PMC
  5. 05
    Imai K7 papers · 2025

    Department of Pediatrics, National Defense Medical College, Tokorozawa, Japan.

    Papers in Europe PMC
  6. 06
    Jiao J7 papers · 2025

    School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, China.

    Papers in Europe PMC
  7. 07
    Wang Y7 papers · 2025

    Department of Pediatrics, the First Hospital of Jilin University, Changchun, 130021, China.

    Papers in Europe PMC
  8. 08
    Lv Z6 papers · 2025

    School of Forensic Medicine, Xinxiang Medical University, Xinxiang, China.

    Papers in Europe PMC
  9. 09
    Plebani A6 papers · 2018

    Department of Clinical and Experimental Sciences, Pediatrics Clinic and Institute of Molecular Medicine A. Novicelli, University of Brescia, ASST-Spedali Civili of Brescia, Brescia, Italy.

    Papers in Europe PMC
  10. 10
    Catalan N5 papers · 2004

    Institut National de la Santé et de la Recherche Médicale, Unité 429, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, 75015 Paris, France.

    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. 1 observational study did — shown below because natural-history and cohort work can be an important step toward a trial. 5 trials are registered for hyper-IgM syndrome, 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.

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.

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

Broader category: hyper-IgM syndrome

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.

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.

Recruiting or not-yet-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 16 · after dedupe 16 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 16 · 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).

Uncertain / not reviewed (16)

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 Hyper-IgM syndrome type 2 — 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.

("Hyper-IgM syndrome type 2" OR "AID deficiency" OR "Activation-induced cytidine deaminase deficiency" OR "HIGM2" OR "AICDA hyper-IgM syndrome" OR "hyper-IgM syndrome caused by mutation in AICDA") OR ("AICDA" OR "AICDA syndrome" OR "AICDA-related")

Run this search on Europe PMC

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

"Hyper-IgM syndrome type 2" OR "AID deficiency" OR "Activation-induced cytidine deaminase deficiency" OR "HIGM2" OR "AICDA hyper-IgM syndrome" OR "hyper-IgM syndrome caused by mutation in AICDA"

Study-type breakdown: 0 interventional · 1 observational · 0 expanded access. Only interventional studies enter the trial headline.

Parent-category trials query:

"hyper-IgM syndrome"

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 (3746) is extremely high with unknown/missing prevalence — treat as possible over-matching, not proven research intensity

Ingested 2026-07-27T07:18:18.262Z