GBE1

Chr 3AR

1,4-alpha-glucan branching enzyme 1

Also known as: APBD, GBE, GSD4

NCBI Gene: 2632 ENSG00000114480 UniProt: Q04446 OMIM: 607839

The encoded glycogen branching enzyme catalyzes the transfer of alpha-1,4-linked glucosyl units to alpha-1,6 positions on glycogen chains, creating branches that increase glycogen solubility and reduce osmotic pressure in cells. Mutations cause glycogen storage disease IV (Andersen disease) and adult-onset polyglucosan body disease through autosomal recessive inheritance. The pathogenic mechanism involves dominant-negative effects of mutant protein.

OMIM ResearchSummary from RefSeq, OMIM, Mechanism

The protein encoded by this gene is a glycogen branching enzyme that catalyzes the transfer of alpha-1,4-linked glucosyl units from the outer end of a glycogen chain to an alpha-1,6 position on the same or a neighboring glycogen chain. Branching of the chains is essential to increase the solubility of the glycogen molecule and, consequently, in reducing the osmotic pressure within cells. Highest level of this enzyme are found in liver and muscle. Mutations in this gene are associated with glycogen storage disease IV (also known as Andersen's disease). [provided by RefSeq, Jul 2008]

OMIM ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

Glycogen storage disease IVMIM #232500

Polyglucosan body disease, adult formMIM #263570

Clinical highlights

Gene-disease validity (ClinGen)

glycogen storage disease due to glycogen branching enzyme deficiency · ARDefinitivesufficient evidence for diagnostic panels

Interpreting a novel variant

Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

0.97

LOEUF

LOF

Mechanism· G2P