Disease Overview

Pompe disease is a progressive, multisystemic, debilitating, and often fatal neuromuscular disorder. It was first defined in 1932 by Dutch pathologist Joannes C. Pompe in a seven-month-old infant who died of idiopathic cardiac hypertrophy and was found to have massive glycogen accumulation in many tissues, but predominantly skeletal and cardiac muscles.[1], [2] In 1963 the disease was linked to an inherited deficiency of the lysosomal enzyme[3] acid alpha-glucosidase (GAA), which is responsible for the breakdown of glycogen to glucose. The result is intralysosomal accumulation of glycogen, primarily in muscle cells, that leads to a progressive loss of muscle function.

Classification & Nomenclature

Pompe disease can be classified into several categories:

  • Lysosomal storage disorders (LSDs) – There are more than 40 rare genetic disorders, all of which are caused by the deficiency or malfunction of a particular lysosomal enzyme.
  • Glycogen storage diseases – A group of inherited disorders of glycogen metabolism. This classification focuses on the accumulated substance (glycogen) rather than the site of accumulation (lysosomes).
  • Neuromuscular / metabolic muscle disease – These Diseases share a common feature of muscular degeneration (regardless of underlying pathology).
  • Cardiac disorders – This classification is often used because of the striking cardiomyopathy and cardiomegaly seen in the majority of infants with Pompe disease.

As a result of these various classifications, Pompe disease is often referred as:[4]

  • Acid maltase deficiency (AMD)
  • Glycogen storage disease (GSD) type II
  • Glycogenosis type II
  • Acid alpha-glucosidase deficiency
  • Lysosomal alpha-glucosidase deficiency

In published scientific reports, the enzyme acid alpha-glucosidase (also called acid maltase) is commonly shortened to GAA for glucosidase acid alpha. GAA also referes to the name of the gene that encodes for acid alpha-glucosidase. The GAA enzyme may also be referred to as acid α-glucosidase and abbreviated as α-glu or AGLU. Please note: this website uses the “GAA” abbreviation.

References

  1. Hirschhorn, Rochelle and Arnold J. J. Reuser. Glycogen Storage Disease Type II: Acid Alpha-glucosidase (Acid Maltase) Deficiency. In: Scriver C, Beaudet A, Sly W, Valle D, editors. The Metabolic and Molecular Bases of Inherited Disease. 8th Edition. New York: McGraw-Hill, 2001. 3389-3420.
  2. Pompe J-C. Over idiopatische hypertropie van het hart. Ned Tijdscr Geneeskd 1932; 76:304. 
  3. Hers HG. Alpha-glucosidase deficiency in generalized glycogen-storage disease (Pompe’s disease). Biochem J 1963; 86:11-16.
  4. Hirschhorn, Rochelle and Arnold J. J. Reuser. Glycogen Storage Disease Type II: Acid Alpha-glucosidase (Acid Maltase) Deficiency. In: Scriver C, Beaudet A, Sly W, Valle D, editors. The Metabolic and Molecular Bases of Inherited Disease. 8th Edition. New York: McGraw-Hill, 2001. 5568.

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