GCNT1

Chr 9

glucosaminyl (N-acetyl) transferase 1

Also known as: C2GNT, C2GNT-L, C2GNT1, C2GlcNAcT, G6NT, NACGT2, NAGCT2

This gene is a member of the beta-1,6-N-acetylglucosaminyltransferase gene family. It is essential to the formation of Gal beta 1-3(GlcNAc beta 1-6)GalNAc structures and the core 2 O-glycan branch. The gene coding this enzyme was originally mapped to 9q21, but was later localized to 9q13. Multiple alternatively spliced variants, encoding the same protein, have been identified. [provided by RefSeq, Jul 2008]

0
Active trials
37
Pathogenic / LP
99
ClinVar variants
2
Pubs (1 yr)
0.8
Missense Z
0.92
LOEUF
Clinical SummaryGCNT1
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
37 Pathogenic / Likely Pathogenic· 58 VUS of 99 total submissions

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.
0.92LOEUF
pLI 0.003
Z-score 1.78
OE 0.47 (0.250.92)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.
0.79Z-score
OE missense 0.85 (0.760.96)
201 obs / 235.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.
LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.47 (0.250.92)
00.351.4
Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.85 (0.760.96)
00.61.4
Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.1.03
01.21.6
LoF obs/exp: 6 / 12.9Missense obs/exp: 201 / 235.1Syn Z: -0.19
DN
0.5966th %ile
GOF
0.6736th %ile
LOF
0.2386th %ile

The highest-scoring mechanism for this gene is gain-of-function.

GOFprediction above median

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

99 submitted variants in ClinVar

Classification Summary

Pathogenic33
Likely Pathogenic4
VUS58
Likely Benign3
Benign1
33
Pathogenic
4
Likely Pathogenic
58
VUS
3
Likely Benign
1
Benign

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
0
0
33
0
33
Likely Pathogenic
0
0
4
0
4
VUS
0
49
9
0
58
Likely Benign
0
2
0
1
3
Benign
0
0
0
1
1
Total05146299

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

View in ClinVar →

Protein Context — Lollipop Plot

GCNT1 · protein map & ClinVar variants

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

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →
Clinical Literature
Landmark / reviewRecent case evidence