eMedicine Specialties > Endocrinology > Metabolic Disorders

Glycogen Storage Disease, Type V

Author: Wayne E Anderson, DO, Assistant Professor of Internal Medicine/Neurology, Western University of Health Sciences; Assistant Professor of Family Medicine, Touro University College of Osteopathic Medicine; Consulting Staff in Pain Management, Department of Neurology, California Pacific Medical Center; Consulting Staff in Neurology, Department of Neurology, California Pacific Medical Center
Contributor Information and Disclosures

Updated: Nov 12, 2009

Introduction

Background

A glycogen storage disease (GSD) is the result of an enzyme defect. These enzymes normally catalyze reactions that ultimately convert glycogen compounds to glucose. Enzyme deficiency results in glycogen accumulation in tissues. In many cases, the defect has systemic consequences, but in some cases, the defect is limited to specific tissues. Most patients experience muscle symptoms, such as weakness and cramps, although certain GSDs manifest as specific syndromes, such as hypoglycemic seizures or cardiomegaly. (See image below and Image 1.)

Metabolic pathways of carbohydrates.

Metabolic pathways of carbohydrates.

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Metabolic pathways of carbohydrates.

Metabolic pathways of carbohydrates.


The following list contains a quick reference for 8 of the GSD types:

  • 0 - Glycogen synthase deficiency
  • Ia - Glucose-6-phosphatase deficiency (von Gierke disease)
  • II - Acid maltase deficiency (Pompe disease)
  • III - Debranching enzyme deficiency (Forbes-Cori disease)
  • IV - Transglucosidase deficiency (Andersen disease, amylopectinosis)
  • V - Myophosphorylase deficiency (McArdle disease)
  • VI - Phosphorylase deficiency (Hers disease)
  • VII - Phosphofructokinase deficiency (Tarui disease)

Although at least 14 unique GSDs are discussed in the literature, the 4 that cause clinically significant muscle weakness are Pompe disease (GSD type II, acid maltase deficiency), Cori disease (GSD type III, debranching enzyme deficiency), McArdle disease (GSD type V, myophosphorylase deficiency), and Tarui disease (GSD type VII, phosphofructokinase deficiency). One form, von Gierke disease (GSD type Ia, glucose-6-phosphatase deficiency), causes clinically significant end-organ disease with significant morbidity. The remaining GSDs are not benign but are less clinically significant; therefore, the physician should consider the aforementioned GSDs when initially entertaining the diagnosis of a GSD. Interestingly, GSD type 0 also is described and is a disorder causing glycogen deficiency due to defective glycogen synthase.

These inherited enzyme defects usually present in childhood, although some, such as McArdle disease and Pompe disease, have separate adult-onset forms. In general, GSDs are inherited as autosomal recessive conditions. Several different mutations have been reported for each disorder.1

Unfortunately, no specific treatment or cure exists, although diet therapy may be highly effective at reducing clinical manifestations. In some cases, liver transplantation may abolish biochemical abnormalities. Active research continues.

Diagnosis depends on findings from patient history and physical examination, creatine kinase testing, muscle biopsy, electromyelography, and ischemic forearm testing. Biochemical assay for enzyme activity is the method of definitive diagnosis.

Myophosphorylase, the deficient enzyme in McArdle disease, is found in muscle tissue. Myophosphorylase deficiency causes muscle cramps, pain, and stiffness. One hallmark of McArdle disease is weakness with exertion. Proximal muscle weakness may progress with time, and no specific treatment exists.

Recent research
To study the role of fat metabolism in GSD type V, Andersen et al manipulated the availability of free fatty acid for oxidation during exercise in 10 patients with the disease.2 The patients, who cycled at a constant workload corresponding to 70% of their maximum oxygen consumption, received either nicotinic acid or 20% Intralipid infusion, which, respectively, reduced or increased free fatty acid availability.

Comparing their trial results with those of placebo and glucose infusion studies, the authors concluded that although during exercise lipids are an important fuel source in persons with GSD type V, maximal fat oxidation rates during exercise cannot be raised above physiologically normal rates in these patients. Andersen et al suggested that this limitation results from glycolytic flux impairment, which causes a "metabolic bottleneck" in the tricarboxylic acid cycle.

Pathophysiology

The phenotype of the individual with GSD results from an enzyme defect. Carbohydrate metabolic pathways are blocked, leading to excess glycogen accumulation in affected tissues and/or disturbances in energy production. Several gene mutations have been described.1

Fatty acids and glucose serve as substrates for energy production. With intense exercise, glucose from glycogen stores in muscle becomes the predominant resource. Fatigue develops when the glycogen supply is exhausted.3 Each GSD represents a specific enzyme defect, and each enzyme is in specific, or most, body tissues. Myophosphorylase is found in muscle. Hypoglycemia is not an expected finding because liver phosphorylase is not involved.

Frequency

International

Herling and colleagues studied the incidence and frequency of inherited metabolic conditions in British Columbia. GSDs are found in 2.3 children per 100,000 births per year.

Mortality/Morbidity

Immediate morbidity arises from severe exercise intolerance.

Age

  • In general, GSDs present in childhood. Later onset correlates with a less severe form. Consider Pompe disease if onset is in infancy.
  • The majority of patients with McArdle disease present in the second to third decade of life.
  • Wolfe and colleagues report a unique case of McArdle disease presenting in a person aged 73 years.4 Felice and colleagues and Pourmand and colleagues also report late presentations. Physicians should have clinical suspicion regardless of age of presentation.5,6

Clinical

History

  • Age at onset of symptoms depends on enzyme activity levels. Initial symptoms are cramps, fatigue, and pain after exercise.
  • Because severity depends on enzyme activity, individual presentation is unique.
  • Some adults develop a progressive proximal weakness.
  • Some adults develop a fixed motor weakness.
  • The disorder has a unique "second-wind" phenomenon.7 If a patient nearing fatigue slows exercise to a tolerable level, a point exists at which exercise may be increased again without previous symptoms. According to Braakhekke and colleagues, this phenomenon may be secondary to increased recruitment of motor units, increased cardiac output, and use of free fatty acids for muscle metabolism.8
  • Burgundy-colored urine has been reported. It is thought to be a result of rhabdomyolysis after intense exercise.
  • Voduc and colleagues report an unusual presentation as unexplained dyspnea.9
  • The rate of rise in oxygen consumption per unit time (VO2) is relative to work rate increases.

Physical

  • Diagnosis is suggested by patient history.
  • Clinical findings may be absent upon physical examination.
  • Muscle strength and reflexes may be normal.
  • In later adult life, persistent weakness and muscle wasting may be present.
  • When clinical suspicion is present, diagnostic testing includes the ischemic forearm test, laboratory analysis, and electromyography.

Causes

  • GSD type V is an autosomal recessive disease, with heterozygotes usually not manifesting clinical features of the disease.

More on Glycogen Storage Disease, Type V

Overview: Glycogen Storage Disease, Type V
Differential Diagnoses & Workup: Glycogen Storage Disease, Type V
Treatment & Medication: Glycogen Storage Disease, Type V
Follow-up: Glycogen Storage Disease, Type V
Multimedia: Glycogen Storage Disease, Type V
References
Further Reading
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References

  1. Duno M, Quinlivan R, Vissing J, et al. High-resolution melting facilitates mutation screening of PYGM in patients with McArdle disease. Ann Hum Genet. May 2009;73:292-7. [Medline].

  2. Andersen ST, Jeppesen TD, Taivassalo T, et al. Effect of changes in fat availability on exercise capacity in McArdle disease. Arch Neurol. Jun 2009;66(6):762-6. [Medline].

  3. Kemp GJ, Tonon C, Malucelli E, et al. Cytosolic pH buffering during exercise and recovery in skeletal muscle of patients with McArdle's disease. Eur J Appl Physiol. Mar 2009;105(5):687-94. [Medline].

  4. Wolfe GI, Baker NS, Haller RG. McArdle's disease presenting with asymmetric, late-onset arm weakness. Muscle Nerve. Apr 2000;23(4):641-5. [Medline].

  5. Felice KJ, Schneebaum AB, Jones HR Jr. McArdle's disease with late-onset symptoms: case report and review of the literature. J Neurol Neurosurg Psychiatry. May 1992;55(5):407-8. [Medline].

  6. Pourmand R, Sanders DB, Corwin HM. Late-onset Mcardle''s disease with unusual electromyographic findings. Arch Neurol. Jun 1983;40(6):374-7. [Medline].

  7. Orngreen MC, Jeppesen TD, Andersen ST, et al. Fat metabolism during exercise in patients with McArdle disease. Neurology. Feb 24 2009;72(8):718-24. [Medline].

  8. Braakhekke JP, de Bruin MI, Stegeman DF. The second wind phenomenon in McArdle's disease. Brain. 109 (Pt 6):1087-101. [Medline].

  9. Voduc N, Webb KA, D'Arsigny C, et al. McArdle's disease presenting as unexplained dyspnea in a young woman. Can Respir J. Mar 2004;11(2):163-7. [Medline].

  10. Bruno C, Bertini E, Santorelli FM. HyperCKemia as the only sign of McArdle''s disease in a child. J Child Neurol. Feb 2000;15(2):137-8. [Medline].

  11. Felice KJ, Grunnet ML, Sima AA. Selective atrophy of type 1 muscle fibers in McArdle's disease. Neurology. Aug 1996;47(2):581-3. [Medline].

  12. Zingone A, Hiraiwa H, Pan CJ. Correction of glycogen storage disease type 1a in a mouse model by gene therapy. J Biol Chem. Jan 14 2000;275(2):828-32. [Medline].

  13. Bijvoet AG, Van Hirtum H, Vermey M. Pathological features of glycogen storage disease type II highlighted in the knockout mouse model. J Pathol. Nov 1999;189(3):416-24. [Medline].

  14. Andersen ST, Vissing J. Carbohydrate- and protein-rich diets in McArdle disease: effects on exercise capacity. J Neurol Neurosurg Psychiatry. Dec 2008;79(12):1359-63. [Medline].

  15. Day TJ, Mastaglia FL. Depot-glucagon in the treatment of McArdle''s disease. Aust N Z J Med. Dec 1985;15(6):748-50. [Medline].

  16. Pillarisetti J, Ahmed A. McArdle disease presenting as acute renal failure. South Med J. Mar 2007;100(3):313-6. [Medline].

  17. Amato AA. Acid maltase deficiency and related myopathies. Neurol Clin. Feb 2000;18(1):151-65. [Medline].

  18. Aminoff MJ, ed. Electromyography in Clinical Practice. 3rd ed. New York, NY: Churchill Livingstone; 1998.

  19. Applegarth DA, Toone JR, Lowry RB. Incidence of inborn errors of metabolism in British Columbia, 1969-1996. Pediatrics. Jan 2000;105(1):e10. [Medline].

  20. Chen Y. Glycogen Storage Diseases. In: Scriver CR, Beaudet AL, Sly WS, Valle D, Childs B, Vogelstein B, eds. The Metabolic and Molecular Bases of Inherited Disease. Vol 1. 8th ed. New York, NY: McGraw-Hill; 2000:1537-8.

  21. Chiado-Piat L, Mongini T, Doriguzzi C. Clinical spectrum of McArdle disease: three cases with unusual expression. Eur Neurol. 1993;33(3):208-11. [Medline].

  22. Chui LA, Munsat TL. Dominant inheritance of McArdle syndrome. Arch Neurol. Sep 1976;33(9):636-41. [Medline].

  23. Goldberg T, Slonim AE. Nutrition therapy for hepatic glycogen storage diseases. J Am Diet Assoc. Dec 1993;93(12):1423-30. [Medline].

  24. Isackson PJ, Tarnopolsky M, Vladutiu GD. A novel mutation in the PYGM gene in a family with pseudo-dominant transmission of McArdle disease. Mol Genet Metab. Jul 2005;85(3):239-42. [Medline].

  25. Martin MA, Rubio JC, Campos Y. Two homozygous mutations (R193W and 794/795 delAA) in the myophosphorylase gene in a patient with McArdle's disease. Hum Mutat (Online). Mar 2000;15(3):294. [Medline].

  26. O'Dochartaigh CS, Ong HY, Lovell SM, et al. Oxygen consumption is increased relative to work rate in patients with McArdle's disease. Eur J Clin Invest. Nov 2004;34(11):731-7. [Medline].

  27. Orho M, Bosshard NU, Buist NR. Mutations in the liver glycogen synthase gene in children with hypoglycemia due to glycogen storage disease type 0. J Clin Invest. Aug 1 1998;102(3):507-15. [Medline].

  28. Pillarisetti J, Ahmed A. McArdle disease presenting as acute renal failure. South Med J. Mar 2007;100(3):313-6. [Medline].

  29. Quintans B, Sanchez-Andrade A, Teijeira S, Fernandez-Hojas R, Rivas E, López MJ. A new rare mutation (691delCC/insAAA) in exon 17 of the PYGM gene causing McArdle disease. Arch Neurol. Jul 2004;61(7):1108-10. [Medline].

  30. Smit GP, Fernandes J, Leonard JV. The long-term outcome of patients with glycogen storage diseases. J Inherit Metab Dis. 1990;13(4):411-8. [Medline].

  31. Stevens AN, Iles RA, Morris PG. Detection of glycogen in a glycogen storage disease by 13C nuclear magnetic resonance. FEBS Lett. Dec 27 1982;150(2):489-93. [Medline].

  32. Wolfsdorf JI, Holm IA, Weinstein DA. Glycogen storage diseases. Phenotypic, genetic, and biochemical characteristics, and therapy. Endocrinol Metab Clin North Am. Dec 1999;28(4):801-23. [Medline].

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Further Reading

Clinical guidelines:
AASLD practice guidelines: evaluation of the patient for liver transplantation. American Association for the Study of Liver Diseases - Private Nonprofit Research Organization. 2000 Jan (revised 2005 Jun). 26 pages. NGC:004333

Guidelines on diagnosis and treatment of pulmonary arterial hypertension. The Task Force on Diagnosis and Treatment of Pulmonary Arterial Hypertension of the European Society of Cardiology. European Society of Cardiology - Medical Specialty Society. 2004. 36 pages. NGC:004058

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Keywords

glycogen storage disease type V, McArdle's disease, McArdle disease, glycogen storage, glycogen storage disease, glycogen storage type, glycogen metabolism, glycogen storage diseases, glycogen diseases, myophosphorylase

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Contributor Information and Disclosures

Author

Wayne E Anderson, DO, Assistant Professor of Internal Medicine/Neurology, Western University of Health Sciences; Assistant Professor of Family Medicine, Touro University College of Osteopathic Medicine; Consulting Staff in Pain Management, Department of Neurology, California Pacific Medical Center; Consulting Staff in Neurology, Department of Neurology, California Pacific Medical Center
Wayne E Anderson, DO is a member of the following medical societies: American Academy of Neurology, American Medical Association, American Society of Law Medicine and Ethics, California Medical Association, and San Francisco Medical Society
Disclosure: Cephalon Honoraria Speaking and teaching; Pfizer Honoraria Speaking and teaching; King Honoraria Consulting

Medical Editor

David M Klachko, MBBCh, Professor Emeritus, Department of Internal Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Missouri
David M Klachko, MBBCh is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians-American Society of Internal Medicine, American Diabetes Association, American Federation for Medical Research, Endocrine Society, Missouri State Medical Association, and Sigma Xi
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Kent Wehmeier, MD, Professor, Department of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism, St Louis University School of Medicine
Kent Wehmeier, MD is a member of the following medical societies: American Society of Hypertension, Endocrine Society, and International Society for Clinical Densitometry
Disclosure: Nothing to disclose.

CME Editor

Mark Cooper, MBBS, PhD, FRACP, Head, Diabetes & Metabolism Division, Baker Heart Research Institute, Professor of Medicine, Monash University
Disclosure: Nothing to disclose.

Chief Editor

George T Griffing, MD, Professor of Medicine, St Louis University School of Medicine
George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Medical Practice Executives, American College of Physician Executives, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical Research, Endocrine Society, International Society for Clinical Densitometry, and Southern Society for Clinical Investigation
Disclosure: Nothing to disclose.

 
 
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