Glycogen storage diseases

Glycogen storage diseases a group of diseases characterized by the accumulation of glycogen.

Clinical picture

• Exercise intolerance
• Usually due to specific muscle enzyme defects

DDx:

• Mitochondriopathies
• Carnitine palmitoyltransferase II (CPT2) deficiency

General microscopic

Features:

• +/-Vacuolated muscle fibres.
• acid phosphatase+ve in vaculoes.
• PAS+ve.

Images:

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  Abnormal glycogen is not easy to spot in this muscle biopsy HE stain (WC/jensflorian)

• 

  Intramuscular glycogen is usually PAS+++ve (WC/jensflorian)

• 

  Lack of staining in intramuscular deposits, Trichrom Gömöri (WC/jensflorian)

• 

  Lafora-like polyglucosan bodies in the CNS, low magnification (WC/jensflorian)

• 

  Lafora-like polyglucosan bodies in the CNS, higher magnification(WC/marvin101)

• 

  Large vacuoles in the liver, HE stain (WC/Netha Hussain)

• Glycogen storage disease (wustl.edu).
• Glycogen storage disease (brown.edu).

Electron microscopy

• Electron dense deposits.

Specific diseases

Pompe disease

• AKA glycogenosis II, AKA acid maltase deficiency, AKA alpha-1,4-glucosidase deficiency.

General

Deficiency of alpha-1,4-glucosidase; it degrades glycogen to glucose in lysosomes.

Clinical:

• Floppy baby.
• Big heart.
  • Often early death from cardiac failure.

• 

  Large vacuoles in Pompe disease (H&E, WC/jensflorian)

• 

  Clinical phenotype in Pompe disease (WC/Wens et. al.)

Cori disease

• AKA glycogen storage disease type III.

General

• Hepatomegaly.

Microscopic

Features:

• Hypertrophic hepatocytes with pale cytoplasm.
  • Classically: PAS +ve, PAS-D -ve.
• Portal fibrosis.

Image:

• Glycogen storage disease consistent with Cori disease - high mag. (WC).

Stains

• PAS +ve.
• PAS-D -ve.

See also

• Lysosomal storage diseases.