HS3ST1
Chr 4heparan sulfate-glucosamine 3-sulfotransferase 1
Also known as: 3OST, 3OST1
The protein catalyzes the transfer of sulfate groups to specific glucosamine residues in heparan sulfate and performs the rate-limiting step in anticoagulant heparan sulfate biosynthesis. Mutations cause autosomal recessive developmental and epileptic encephalopathy with severe intellectual disability, typically presenting in infancy. The gene shows tolerance to loss-of-function variants, consistent with the recessive inheritance pattern observed in affected patients.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.
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
0 submitted variants in ClinVar
Protein Context — Lollipop Plot
HS3ST1 · 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