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IEMbase 0498: GYS1-related muscle glycogen synthase deficiency

Scope

Field Value
IEMbase ID 498
Nosology 3.4.02.01
Gene GYS1
External IDs OMIM:611556; ORPHA:137625
Generated mapping CANDIDATE; MEDIUM; Glycogen_Storage_Disease_Type_I.yaml
Candidate DisMech targets Glycogen_Storage_Disease_Type_I.yaml
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents autosomal recessive GYS1-related muscle glycogen synthase deficiency as glycogen storage disease type 0b. No treatments are listed. Biochemical rows include decreased muscle glycogen synthase and profoundly decreased muscle glycogen across life stages. No clinical rows are listed in the local JSON.

DisMech phenotype coverage

Glycogen_Storage_Disease_Type_I.yaml is not the correct target. It models G6PC1/SLC37A4 glucose-6-phosphatase system deficiency and hepatic/renal fasting-hypoglycemia biology. It does not model GYS1, muscle glycogen synthase deficiency, GSD 0b, or depleted muscle glycogen. Lafora_Disease.yaml contains GYS1 biology in the context of overactive glycogen synthesis and Lafora-body formation, but that is an opposite-direction, different disease mechanism and is not exact coverage.

Concordance and completeness

Judgement: false-positive candidate; true GYS1/GSD 0b local gap.

The generated GSD I candidate shares only broad glycogen-storage terminology. IEMbase's disease is a muscle glycogen synthesis defect with reduced glycogen, whereas GSD I is a glucose-release defect with hepatic glycogen/fat accumulation. The local Lafora disease entry confirms that GYS1 appears in the KB, but not as GYS1 loss-of-function muscle glycogen synthase deficiency.

Curation actions

  • Do not map this record to Glycogen_Storage_Disease_Type_I.yaml.
  • Track GYS1-related muscle glycogen synthase deficiency / GSD 0b as a local curation gap.
  • Preserve IEMbase prompts for muscle glycogen synthase activity and profoundly decreased muscle glycogen for a future exact entry.