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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed February 2010

What is the official name of the GAA gene?

The official name of this gene is “glucosidase, alpha; acid.”

GAA is the gene's official symbol. The GAA gene is also known by other names, listed below.

What is the normal function of the GAA gene?

The GAA gene provides instructions for producing an enzyme called acid alpha-glucosidase (also known as acid maltase). This enzyme is active in lysosomes, which are structures that serve as recycling centers within cells. Lysosomes use digestive enzymes to break down complex molecules into simpler ones that can be used by cells. Acid alpha-glucosidase normally breaks down a complex sugar called glycogen into a simpler sugar called glucose. Glucose is the main energy source for most cells.

How are changes in the GAA gene related to health conditions?

Pompe disease - caused by mutations in the GAA gene

More than 200 mutations in the GAA gene have been identified in people with Pompe disease. Many of these mutations change one of the protein building blocks (amino acids) used to make acid alpha-glucosidase. Other mutations insert or delete genetic material in the GAA gene. Mutations in this gene significantly reduce the activity of acid alpha-glucosidase, preventing the enzyme from breaking down glycogen effectively. As a result, this complex sugar can build up to toxic levels in lysosomes. The abnormal buildup of glycogen damages organs and tissues throughout the body, particularly the muscles, leading to progressive muscle weakness, heart problems, and the other features of Pompe disease.

Where is the GAA gene located?

Cytogenetic Location: 17q25.2-q25.3

Molecular Location on chromosome 17: base pairs 80,101,531 to 80,119,881

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The GAA gene is located on the long (q) arm of chromosome 17 between positions 25.2 and 25.3.

The GAA gene is located on the long (q) arm of chromosome 17 between positions 25.2 and 25.3.

More precisely, the GAA gene is located from base pair 80,101,531 to base pair 80,119,881 on chromosome 17.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about GAA?

You and your healthcare professional may find the following resources about GAA helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the GAA gene or gene products?

  • acid alpha-glucosidase
  • acid alpha-glucosidase preproprotein
  • acid maltase
  • Aglucosidase alfa
  • Alpha-1,4-glucosidase
  • Amyloglucosidase
  • Glucoamylase
  • glucosidase, alpha; acid (Pompe disease, glycogen storage disease type II)
  • LYAG
  • lysosomal alpha-glucosidase

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding GAA?

acids ; digestive ; enzyme ; gene ; glucose ; glycogen ; protein ; toxic

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Fukuda T, Roberts A, Plotz PH, Raben N. Acid alpha-glucosidase deficiency (Pompe disease). Curr Neurol Neurosci Rep. 2007 Jan;7(1):71-7. Review. (
  • Hoefsloot LH, Hoogeveen-Westerveld M, Reuser AJ, Oostra BA. Characterization of the human lysosomal alpha-glucosidase gene. Biochem J. 1990 Dec 1;272(2):493-7. (
  • Montalvo AL, Bembi B, Donnarumma M, Filocamo M, Parenti G, Rossi M, Merlini L, Buratti E, De Filippi P, Dardis A, Stroppiano M, Ciana G, Pittis MG. Mutation profile of the GAA gene in 40 Italian patients with late onset glycogen storage disease type II. Hum Mutat. 2006 Oct;27(10):999-1006. (
  • Moreland RJ, Jin X, Zhang XK, Decker RW, Albee KL, Lee KL, Cauthron RD, Brewer K, Edmunds T, Canfield WM. Lysosomal acid alpha-glucosidase consists of four different peptides processed from a single chain precursor. J Biol Chem. 2005 Feb 25;280(8):6780-91. Epub 2004 Nov 1. (
  • NCBI Gene (
  • Oba-Shinjo SM, da Silva R, Andrade FG, Palmer RE, Pomponio RJ, Ciociola KM, S Carvalho M, Gutierrez PS, Porta G, Marrone CD, Munoz V, Grzesiuk AK, Llerena JC Jr, Berditchevsky CR, Sobreira C, Horovitz D, Hatem TP, Frota ER, Pecchini R, Kouyoumdjian JA, Werneck L, Amado VM, Camelo JS Jr, Mattaliano RJ, Marie SK. Pompe disease in a Brazilian series: clinical and molecular analyses with identification of nine new mutations. J Neurol. 2009 Nov;256(11):1881-90. doi: 10.1007/s00415-009-5219-y. Epub 2009 Jul 9. (
  • van der Ploeg AT, Reuser AJ. Pompe's disease. Lancet. 2008 Oct 11;372(9646):1342-53. doi: 10.1016/S0140-6736(08)61555-X. Review. (
  • Yan B, Raben N, Plotz P. The human acid alpha-glucosidase gene is a novel target of the Notch-1/Hes-1 signaling pathway. J Biol Chem. 2002 Aug 16;277(33):29760-4. Epub 2002 Jun 13. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: February 2010
Published: February 8, 2016