B4GAT1

Chr 11

beta-1,4-glucuronyltransferase 1

Also known as: B3GN-T1, B3GNT1, B3GNT6, BETA3GNTI, MDDGA13, iGAT, iGNT

NCBI Gene: 11041 ENSG00000174684 UniProt: O43505

The protein is a beta-1,4-glucuronyltransferase that synthesizes glucuronyl-xylose disaccharide primers essential for O-mannosylation of alpha-dystroglycan, enabling high-affinity binding to laminin and other extracellular matrix proteins. Mutations cause congenital muscular dystrophy-dystroglycanopathy type A13 with brain and eye anomalies, affecting muscle, central nervous system, and ocular development from birth. Inheritance is autosomal recessive.

ResearchSummary from RefSeq, OMIM, UniProt

This gene encodes a member of the beta-1,3-N-acetylglucosaminyltransferase family. This enzyme is a type II transmembrane protein. It is essential for the synthesis of poly-N-acetyllactosamine, a determinant for the blood group i antigen. [provided by RefSeq, Jul 2008]

ResearchGenerating clinical summary…

LOEUF 0.80

Clinical Summary— B4GAT1

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Gene-Disease Validity (ClinGen)

muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A13 · ARModerate

Moderate evidence — consider for supplementary testing

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Population Constraint (gnomAD)

Low constraint (pLI 0.01) — loss-of-function variants are relatively tolerated in the population.

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ClinVar Variants

8 unique Pathogenic / Likely Pathogenic· 111 VUS of 249 total submissions

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Clinical Trials

1 active or recruiting trial — potential therapeutic options may be available

Explore recent and relevant literature in Research Assistant →

Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

Tolerant — LoF & missense variants common in population

LoF Constraint?

0.80LOEUF

pLI 0.007

Z-score 2.12

OE 0.41 (0.22–0.80)

Tolerant

Typical tolerance to LoF variation

Missense Constraint?

1.90Z-score

OE missense 0.66 (0.58–0.75)

161 obs / 244.8 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?

LoF OE?0.41 (0.22–0.80)

0≤0.351.4

Missense OE?0.66 (0.58–0.75)

0≤0.61.4

Synonymous OE?0.74

0≤1.21.6

LoF obs/exp: 6 / 14.8Missense obs/exp: 161 / 244.8Syn Z: 2.22

ClinVar Variant Classifications

249 submitted variants in ClinVar

ClinVar

Classification Summary

Pathogenic3

Likely Pathogenic5

VUS111

Likely Benign117

Benign4

Conflicting7

Pathogenic

Likely Pathogenic

111

VUS

117

Likely Benign

Benign

Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

Classification	LoF	Missense + Inframe	Non-coding	Synonymous	Total
Pathogenic	2	1	0	0	3
Likely Pathogenic	2	3	0	0	5
VUS	4	107	0	0	111
Likely Benign	0	4	14	99	117
Benign	0	0	3	1	4
Conflicting	—				7
Total	8	115	17	100	247

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

View in ClinVar →

12 pathogenic / likely-pathogenic (of 18) ClinVar copy-number / structural variants overlap B4GAT1 — these span large chromosomal regions, not the gene specifically, and are excluded from the counts above. Explore in CNV tools →