B3GLCT

Chr 13AR

beta 3-glucosyltransferase

Also known as: B3GALTL, B3GTL, B3Glc-T, Gal-T, beta3Glc-T

The protein is a beta-1,3-glucosyltransferase that transfers glucose to O-linked fucosylglycans on thrombospondin type-1 repeats, extending a unique post-translational modification pathway in the endoplasmic reticulum. Mutations cause Peters-plus syndrome, a rare disorder involving anterior segment eye malformations, intellectual disability, and growth deficiency. The condition follows autosomal recessive inheritance.

OMIMResearchSummary from RefSeq, UniProt
LOFmechanismARLOEUF 1.291 OMIM phenotype
Clinical SummaryB3GLCT
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Gene-Disease Validity (ClinGen)
Peters plus syndrome · ARDefinitive

Definitive — sufficient evidence for diagnostic panels

Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
31 unique Pathogenic / Likely Pathogenic· 105 VUS of 222 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
1.29LOEUF
pLI 0.000
Z-score 0.35
OE 0.93 (0.681.29)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint
0.39Z-score
OE missense 0.93 (0.841.04)
237 obs / 254.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.93 (0.681.29)
00.351.4
Missense OE0.93 (0.841.04)
00.61.4
Synonymous OE1.20
01.21.6
LoF obs/exp: 26 / 28.0Missense obs/exp: 237 / 254.6Syn Z: -1.55

ClinVar Variant Classifications

222 submitted variants in ClinVar

Classification Summary

Pathogenic23
Likely Pathogenic8
VUS105
Likely Benign56
Benign9
23
Pathogenic
8
Likely Pathogenic
105
VUS
56
Likely Benign
9
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
5
1
17
0
23
Likely Pathogenic
6
2
0
0
8
VUS
2
89
13
1
105
Likely Benign
0
3
22
31
56
Benign
0
1
6
2
9
Total13965834201

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

B3GLCT · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

3D Protein StructureAlphaFold

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

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Clinical Literature
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