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IEMbase 0496: GYG1-related muscle glycogenin 1 deficiency

Scope

Field Value
IEMbase ID 496
Nosology 3.4.01.01
Gene GYG1
External IDs OMIM:613507; ORPHA:263297
Generated mapping CANDIDATE; MEDIUM; Glycogen_Storage_Disease_XV.yaml
Candidate DisMech targets Glycogen_Storage_Disease_XV.yaml
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents autosomal recessive GYG1-related muscle glycogenin 1 deficiency as glycogen storage disease type XV / polyglucosan body myopathy type 2. No treatments are listed. The only biochemical row in the local JSON is markedly decreased muscle glycogen across life stages. No clinical rows are listed in the local JSON.

DisMech phenotype coverage

Glycogen_Storage_Disease_XV.yaml is the correct local target despite the generated CANDIDATE status. The entry models autosomal recessive GYG1 glycogenin-1 deficiency, failed glycogen synthesis initiation, skeletal-muscle polyglucosan body myopathy, proteostasis/desmin sequestration, cardiac polyglucosan involvement, proximal and distal weakness, exercise intolerance, myalgia, waddling gait, scapular winging, skeletal-muscle atrophy/fatty replacement on MRI, creatine kinase, depleted normal skeletal-muscle glycogen, muscle biopsy, GYG1 genetic testing, and supportive management.

Concordance and completeness

Judgement: correct candidate; accept as covered by Glycogen_Storage_Disease_XV.yaml.

IEMbase and DisMech agree on GYG1/GSD XV identity, recessive inheritance, and the key muscle-glycogen abnormality. DisMech captures the broader disease mechanism and clinical spectrum that are sparse in the current IEMbase JSON: polyglucosan body myopathy, weakness, exertional symptoms, cardiac involvement, MRI findings, biopsy, and genetics. The IEMbase "decreased muscle glycogen" row matches the DisMech observation that normal glycogen can be depleted in fibers containing polyglucosan bodies.

Curation actions

  • Treat this as covered by Glycogen_Storage_Disease_XV.yaml.
  • Consider promoting future automated matching from candidate to exact for GYG1, glycogenin-1 deficiency, GSD XV, and polyglucosan body myopathy type 2.
  • If importing IEMbase prompts, verify the decreased-muscle-glycogen wording against the existing normal-glycogen depletion evidence.