B3GAT1
Chr 11beta-1,3-glucuronyltransferase 1
Also known as: CD57, GLCATP, GLCUATP, HNK1, LEU7, NK-1, NK1
The B3GAT1 protein functions as a glucuronyltransferase that catalyzes the biosynthesis of the HNK-1 carbohydrate epitope on glycoproteins and participates in glycosaminoglycan biosynthesis. Mutations cause autosomal recessive multiple congenital anomalies-hypotonia-seizures syndrome, characterized by early-onset developmental delays, hypotonia, seizures, and distinctive facial features. The gene shows moderate constraint against loss-of-function variants, consistent with its role in essential carbohydrate modification pathways.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Typical tolerance to LoF variation
Moderately missense-constrained (top ~2.5%)
The highest-scoring mechanism for this gene is dominant-negative.
Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.
Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.
ClinVar Variant Classifications
136 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 | 81 | 0 | 81 |
Likely Pathogenic | 0 | 0 | 7 | 0 | 7 |
VUS | 0 | 33 | 10 | 0 | 43 |
Likely Benign | 0 | 0 | 1 | 0 | 1 |
Benign | 0 | 0 | 0 | 1 | 1 |
| Total | 0 | 33 | 99 | 1 | 133 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
B3GAT1 · 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