Tay-Sachs disease AB variant
Findings
No curated finding names Tay-Sachs disease AB variant yet. Everything below is reference data from Mondo, HPO and GenCC, not evidence about what affects it.
Definition
GM2 gangliosidosis, AB variant is an extremely rare, severe genetic disorder characterized by progressive neurological decline due to ganglioside activator deficiency.
Definition from the Mondo Disease Ontology (MONDO:0010099), read 2026-09-29. CC BY 4.0.
- Inheritance
- Autosomal recessive inheritance
- Onset and course
- Infantile onset
HPO, annotations 2026-09-02
Features
29 features
What the disease is reported to present with, and how often among people who have it — never how often a feature means the disease. HPO, annotations 2026-09-02.
- Exaggerated startle responseHPOHP:0002267
- 1 of 1 reported patient
- Very frequent (80% to 99% of cases)
- Global developmental delayHPOHP:0001263
- 1 of 1 reported patient
- GM2-ganglioside accumulationHPOHP:0003495
- 1 of 1 reported patient
- HypotoniaHPOHP:0001252
- 1 of 1 reported patient
- Myoclonic seizureHPOHP:0032794
- 1 of 1 reported patient
- Abnormal fear-induced behaviorHPOHP:0100852
- Very frequent (80% to 99% of cases)
- Abnormal pyramidal sign
Show the remaining 17
- HyperacusisHPOHP:0010780
- Very frequent (80% to 99% of cases)
- HyperreflexiaHPOHP:0001347
- Very frequent (80% to 99% of cases)
- NeurodegenerationHPOHP:0002180
- Very frequent (80% to 99% of cases)
- Progressive spastic quadriplegiaHPOHP:0002478
- Very frequent (80% to 99% of cases)
- Short statureHPOHP:0004322
- Very frequent (80% to 99% of cases)
- Abnormal involuntary eye movementsHPOHP:0012547
- Frequent (30% to 79% of cases)
Genes
1 gene
Germline variants in the gene encoding each protein, as classified by GenCC submitters, each in their own words. Limited, disputed and refuted submissions are listed too.
- GM2AHGNC:4367
- Definitive · ClinGen · Autosomal recessive · 2022
- Definitive · G2P · Autosomal recessive · 2015
- Strong · Genomics England PanelApp · Autosomal recessive · 2020
- Strong · Labcorp Genetics (formerly Invitae) · Autosomal recessive · 2020
- Strong · PanelApp Australia · Autosomal recessive · 2025
Where it sits
- A kind of
Other names
1 name
Resolves to: Tay-Sachs disease AB variant
- Also called
- hexosaminidase activator deficiency