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Genetics Library / Genes / AGL

GENE REFERENCE / HGNC:321

AGL

amylo-alpha-1,6-glucosidase and 4-alpha-glucanotransferase

protein-coding gene1p21.2Gene information

What does this gene do?

The AGL gene provides instructions for making the glycogen debranching enzyme. This enzyme is involved in the breakdown of a complex sugar called glycogen, which is a major source of stored energy in the body. Glycogen is made up of several molecules of a simple sugar called glucose. Some glucose molecules are linked together in a straight line, while others branch off and form side chains. The glycogen debranching enzyme is involved in the breakdown of these side chains. The branched structure of glycogen makes it more compact for storage and allows it to break down more easily when it is needed for fuel.

The AGL gene provides instructions for making several different versions (isoforms) of the glycogen debranching enzyme. These isoforms vary by size and are active (expressed) in different tissues.

Source: MedlinePlus, National Library of Medicine. Source publication: 2024-11-01. Source review: 2010-09.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

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.

ConditionInheritanceEvidence
glycogen storage disease IIIMONDO:0009291 · Evaluated 2023-02-24Autosomal recessiveDefinitiveGeneral 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
3,140
Submissions for variants in or overlapping this gene
5,550
Submissions explicitly reporting this gene
5,482
Alleles reported pathogenic / likely pathogenic
703
VariationIDs with uncertain significance
1,094
VariationIDs with conflicting classifications
77

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 AGL?

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 703 alleles in AGL 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 AGL.

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

Sources and dates

The source information on this page last changed on 2026-10-17.

HGNC Source details

Open source record ↗

Source release: Fri, 16 Oct 2026 13:36:12 GMT
Source record updated: 2024-10-17

SHA-256: 72bfe0c05800163c040a2cf663c70501f9ac9236469fbd0b552f2cd37a4d7f67

MedlinePlus Source details

Open source record ↗

Source release: Sat, 17 Oct 2026 05:15:49 GMT
Source publication: 2024-11-01
Source review: 2010-09

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 11 Oct 2026 06:36:01 GMT

SHA-256: b21584f8ebc89a636ce9706023fa9052460587e2ab0fe6d0edf4b9db34336c02

ClinGen Source details

Open source record ↗

Source release: Sat, 17 Oct 2026 07:46:29 GMT

SHA-256: 46d4c75fcae7dd62a9dea4988bbbd440bdc68f2db452fea1556d47b0406de60e

About the library sources · Latest validated release · Record 37e4a17f600e