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GTR Home > Conditions/Phenotypes > Glycogen storage disease, type V

Glycogen storage disease, type V

Synonyms
GSD 5; Glycogen storage disease type 5; MCARDLE DISEASE; MUSCLE GLYCOGEN PHOSPHORYLASE DEFICIENCY; MYOPHOSPHORYLASE DEFICIENCY; McArdle type glycogen storage disease; PYGM DEFICIENCY
Modes of inheritance
Autosomal recessive inheritance (Orphanet)

Summary

Glycogen storage disease type V (GSDV, McArdle disease) is a metabolic myopathy characterized by exercise intolerance manifested by rapid fatigue, myalgia, and cramps in exercising muscles. Symptoms are usually precipitated by isometric exercise or sustained aerobic exercise. Most individuals improve their exercise tolerance by exploiting the "second-wind" phenomenon with relief of myalgia and fatigue after a few minutes of rest. Age of onset is frequently in the first decade of life but can vary; however, diagnosis is typically delayed as myalgia and fatigability are dismissed/overlooked. Fixed muscle weakness occurs in approximately 25% of affected individuals, is more likely to involve proximal muscles, and is more common in individuals of advanced age. Approximately 50% of affected individuals have recurrent episodes of myoglobinuria that can – on occasion – eventually result in acute renal failure. [from GeneReviews]

Available tests

87 tests are in the database for this condition.

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Clinical tests (87 available)

Biochemical Genetics Tests

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: GSD5, PYGM
    Summary: glycogen phosphorylase, muscle associated

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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