ST6GALNAC3
Chr 1ST6 N-acetylgalactosaminide alpha-2,6-sialyltransferase 3
Also known as: PRO7177, SIAT7C, ST6GALNACIII, STY
The protein transfers sialic acid groups to specific carbohydrate structures on glycoproteins and glycolipids, with particular preference for synthesizing ganglioside GD1alpha from GM1b, which is critical for neuronal cell communication and brain function. Biallelic mutations in ST6GALNAC3 cause autosomal recessive intellectual disability with hypotonia and behavioral abnormalities. The gene shows very low constraint against loss-of-function variants, consistent with a recessive inheritance pattern.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Mild missense constraint
ClinVar Variant Classifications
88 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 20 | 0 | 20 |
Likely Pathogenic | 0 | 0 | 3 | 0 | 3 |
VUS | 0 | 42 | 13 | 0 | 55 |
Likely Benign | 0 | 1 | 3 | 0 | 4 |
Benign | 0 | 0 | 1 | 0 | 1 |
| Total | 0 | 43 | 40 | 0 | 83 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
ST6GALNAC3 · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
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