GENE REFERENCE / HGNC:4707

GYS2

glycogen synthase 2

protein-coding gene12p12.1Gene information

What does this gene do?

The GYS2 gene provides instructions for making an enzyme called liver glycogen synthase. Liver glycogen synthase is produced solely in liver cells, where it helps form the complex sugar glycogen by linking together molecules of the simple sugar glucose. Glucose that is taken in from food is stored in the body as glycogen, which is a major source of energy. Glycogen that is stored in the liver can be broken down rapidly when glucose is needed to maintain normal blood glucose levels between meals.

Source: MedlinePlus, National Library of Medicine. Source publication: 2023-07-25. Source review: 2014-01.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
glycogen storage disorder due to hepatic glycogen synthase deficiencyMONDO:0009414 · Evaluated 2024-03-22	Autosomal recessive	DefinitiveGeneral Inborn Errors of Metabolism Gene Curation Expert Panel

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles: 444
Submissions for variants in or overlapping this gene: 781
Submissions explicitly reporting this gene: 719
Alleles reported pathogenic / likely pathogenic: 52
VariationIDs with uncertain significance: 166
VariationIDs with conflicting classifications: 23

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about GYS2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 52 alleles in GYS2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in GYS2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

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