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ORPHA:309246

GM2 gangliosidosis, AB variant

low confidenceDisorder

Also known as: Hexosaminidase activator deficiency

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

Publications

1,788

Trials

0

Interventional, condition-specific

Researchers

352

Distinct authors in sample

Gene link

GM2A

Definitive

Readiness

5/6

Stages with a signal

Clinical definition (Orphanet)

GM2 gangliosidosis, AB variant is an extremely rare, severe genetic disorder characterized by neurological decline due to ganglioside activator deficiency.

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 (1)

hexosaminidase activator deficiency

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 — GM2A

  2. LiteraturePresent

    1,788 matched papers (1,206 in last 10 years) Source

  3. Phenotype characterisedPresent

    50 HPO annotations (e.g. Axial hypotonia; Hyperacusis; Loss of speech) 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; 10 for broader category GM2 gangliosidosis

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 (GM2A).

GenCC classification: Definitive.

Phenotypes (Monarch / HPO)

50

Associated phenotypes · MONDO:0010099

  • Axial hypotonia
  • Hyperacusis
  • Loss of speech
  • Primitive reflex
  • Cherry red spot of the macula

Showing 5 of 50 — 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?

1,788

1,788 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.

1,788 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).

1,206 in the last 10 years · low confidence

Phrase hits: 52 · MeSH hits: 0

Open Europe PMC search

Who's working on it?

352

Distinct author names in 52 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
    Sandhoff K8 papers · 2003

    Kekulé-Institut für Organische Chemie und Biochemie der Universität, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany. sandhoff@uni-bonn.de

    Papers in Europe PMC
  2. 02
    Suzuki K7 papers · 1998

    Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill 27599-7525, USA. KIS@MED.UNC.Edu

    Papers in Europe PMC
  3. 03
    Lemm T3 papers · 1999
    Papers in Europe PMC
  4. 04
    Sheth J3 papers · 2024

    FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad 380015, India.

    Papers in Europe PMC
  5. 05
    Amberger JS2 papers · 1994
    Papers in Europe PMC
  6. 06
    Benkirane M2 papers · 2025

    Laboratoire de Génétique Moléculaire, Université de Montpellier, Institut Universitaire de Recherche Clinique, Centre Hospitalier Universitaire de Montpellier, Montpellier, France.

    Papers in Europe PMC
  7. 07
    Bhavsar R2 papers · 2024

    FRIGE Institute of Human Genetics, FRIGE House, Jodhpur Village Road, Satellite, Ahmedabad, India, 380015.

    Papers in Europe PMC
  8. 08
    Duarte AJ2 papers · 2023

    Departamento de Genética Humana, Unidade de Investigação e Desenvolvimento, Instituto Nacional de Saúde Ricardo Jorge (INSA), 4000-055 Porto, Portugal.

    Papers in Europe PMC
  9. 09
    Giugliani R2 papers · 2022

    Department of Genetics, UFRGS, Medical Genetics Service and Biodiscovery Laboratory, HCPA, Porto Alegre, Brazil.

    Papers in Europe PMC
  10. 10
    Gowda VK2 papers · 2024

    Department of Pediatric Neurology, Indira Gandhi Institute of Child Health, Bangalore, India.

    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). 10 trials are registered for GM2 gangliosidosis, 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.

10 interventional trials matched GM2 gangliosidosis, the broader category — listed below. Those studies are not counted in the condition-specific total.

Broader category: GM2 gangliosidosis

10

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

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 2 · after dedupe 2 · already on CT.gov 0 · kept 0 · parent 0 · uncertain 2 · 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 (2)

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 GM2 gangliosidosis, AB variant — 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.

("GM2 gangliosidosis, AB variant" OR "Hexosaminidase activator deficiency") OR (MESH:"Tay-Sachs Disease, AB Variant") OR ("GM2A" OR "GM2A syndrome" OR "GM2A-related" OR "GM2 syndrome" OR "GM2-related")

Run this search on Europe PMC

MeSH descriptor terms unioned into the query: Tay-Sachs Disease, AB Variant

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

"GM2 gangliosidosis, AB variant" OR "Hexosaminidase activator deficiency" OR "Tay-Sachs Disease, AB Variant"

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

Parent-category trials query:

"GM2 gangliosidosis"

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 (1788) is implausibly high for prevalence class "<1 / 1 000 000" — treat as possible over-matching, not a measure of research intensity

Ingested 2026-07-27T12:55:53.867Z