GM2A
Chr 5ARganglioside GM2 activator
Also known as: GM2-AP, GM2AP, SAP-3
This gene encodes a glycolipid transport protein that acts as a cofactor for lysosomal beta-hexosaminidase A, extracting GM2 ganglioside molecules from membranes and presenting them for degradation. Mutations cause GM2-gangliosidosis AB variant (also called AB variant of Tay-Sachs disease), an autosomal recessive lysosomal storage disorder affecting the nervous system. The gene is not highly constrained against loss-of-function variants, consistent with recessive inheritance where heterozygous carriers are typically unaffected.
Definitive — sufficient evidence for diagnostic panels
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Tolerant to missense variation
Predictions shown for reference only — model trained on dominant genes, not applicable to AR conditions.
The Badonyi & Marsh prediction model was trained exclusively on dominant disease genes. Predictions are not reliable for genes with autosomal recessive inheritance and are shown at reduced opacity for reference only.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
GM2A · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
3D Protein StructureAlphaFold
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
No active trials found for this gene.
Search ClinicalTrials.gov →External Resources
Links to major genomics databases and tools