GYG2
Chr Xglycogenin 2
Also known as: GN-2, GN2
This X-linked gene encodes glycogenin, which catalyzes the formation of short glucose chains that serve as primers for glycogen synthesis, primarily in liver and playing a role in blood glucose homeostasis. Mutations cause glycogen storage disease type XV, characterized by hepatomegaly, fasting hypoglycemia, and elevated liver enzymes typically presenting in infancy or early childhood. The gene shows very low constraint against loss-of-function variants, and inheritance follows an X-linked pattern.
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly tolerant — LoF variants common in population
Mild missense constraint
The highest-scoring mechanism for this gene is gain-of-function.
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
400 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 | 92 | 0 | 92 |
Likely Pathogenic | 0 | 0 | 3 | 0 | 3 |
VUS | 5 | 76 | 35 | 1 | 117 |
Likely Benign | 0 | 6 | 50 | 28 | 84 |
Benign | 0 | 6 | 43 | 5 | 54 |
Conflicting | — | 10 | |||
| Total | 5 | 88 | 223 | 34 | 360 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
GYG2 · 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