GM2A

Chr 5q33.1

ganglioside GM2 activator

Aliases:: SAP-3, GM2-AP, GM2AP
MANE:: ENST00000357164.4

OMIM: 613109 ↗NCBI: 2760 ↗Ensembl ↗

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Predicted protein structure

AlphaFold predicted structure

GM2A · P17900

v62025-08-01

Predicted Aligned Error matrix for GM2A — diagonal shows residue index, colour shows pairwise prediction confidence (lower is better) — Predicted Aligned Error

Mean pLDDT

88.9/ 100

Confident

193 residues

Confidence breakdown

Very high(≥ 90)72%
Confident(70–90)15%
Low(50–70)14%
Very low(< 50)0%

Open interactive 3D viewer

AlphaFold (Jumper et al., 2021) · CC BY 4.0

Clinical relevance (Genomics England PanelApp)

Diagnostic Grade (Green)

Childhood onset dystonia, chorea or related movement disorder
BIALLELIC, autosomal or pseudoautosomal
DDG2P
BIALLELIC, autosomal or pseudoautosomal
Early onset or syndromic epilepsy
BIALLELIC, autosomal or pseudoautosomal
Intellectual disability
BIALLELIC, autosomal or pseudoautosomal
Likely inborn error of metabolism
BIALLELIC, autosomal or pseudoautosomal
Lysosomal storage disorder
BIALLELIC, autosomal or pseudoautosomal
Undiagnosed metabolic disorders
BIALLELIC, autosomal or pseudoautosomal
Fetal anomalies
BIALLELIC, autosomal or pseudoautosomal

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Disease associations (Open Targets)

GM2-gangliosidosis, AB variant
0.81
Tay-Sachs disease AB variant
0.81
neurodegenerative disease
0.55
lysosomal storage disease
0.50
Alzheimer disease
0.48
Parkinson disease
0.48
multiple sclerosis
0.46
Tay-Sachs disease
0.45
Seizure
0.37
femur fracture
0.26

Score is the Open Targets composite evidence score (0-1). Higher = stronger gene-disease association.

Protein function (UniProt)

Ganglioside GM2 activator

Lipid-binding and transfer protein essential for lysosomal degradation of ganglioside GM2. Extracts single GM2 molecules from intralysosomal luminal vesicle (ILV) membranes and presents them in soluble form to beta-hexosaminidase A (HEXA) for cleavage of N-acetyl-D-galactosamine and conversion to GM3 (PubMed:30988135, PubMed:8900233). Forms a stoichiometric GM2-GM2A complex that serves as the substrate for HEXA (PubMed:30988135, PubMed:8900233). Also stimulates the breakdown of glycolipid GA2 by HEXA (By similarity). Possesses dual function: membrane lipid mobilization/solubilization and lipid substrate presentation to hydrolases (PubMed:30988135). The large binding pocket can accommodate several single-chain phospholipids and fatty acids (By similarity). Exhibits some calcium-independent phospholipase activity (By similarity). Participates in cholesterol transfer (PubMed:17552909)