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


Reviewed January 2014

What is the official name of the GYS1 gene?

The official name of this gene is “glycogen synthase 1.”

GYS1 is the gene's official symbol. The GYS1 gene is also known by other names, listed below.

What is the normal function of the GYS1 gene?

The GYS1 gene provides instructions for making an enzyme called muscle glycogen synthase. Muscle glycogen synthase is produced in most cells but is most abundant in heart (cardiac) muscle and muscles used for movement (skeletal muscles). Muscle glycogen synthase helps link together molecules of the simple sugar glucose to form the complex sugar glycogen, which is a major source of stored energy in the body. Most glucose that is taken in from food is stored as glycogen in muscle cells. During contractions of the cardiac muscle or rapid or sustained movement of skeletal muscle, glycogen stored in muscle cells is broken down to supply the cells with energy.

Does the GYS1 gene share characteristics with other genes?

The GYS1 gene belongs to a family of genes called glycosyltransferase group 1 domain containing (glycosyltransferase group 1 domain containing).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the GYS1 gene related to health conditions?

glycogen storage disease type 0 - caused by mutations in the GYS1 gene

At least four mutations in the GYS1 gene have been found to cause a form of glycogen storage disease type 0 (GSD 0) that affects cardiac and skeletal muscle. Most GYS1 gene mutations that cause this condition lead to a lack of functional muscle glycogen synthase, resulting in a complete absence of glycogen in muscle cells. Normally, glycogen is formed from the leftover glucose that is not immediately used by cells after glucose is consumed during meals. In people with GSD 0, who cannot form glycogen, the extra sugar is released by the body. As a result, people with muscle GSD 0 do not have any stored energy, which leads to muscle pain, weakness, or episodes of fainting following moderate physical activity. Since there is no glycogen in cardiac muscle, affected individuals are also at an increased risk of cardiac arrest and sudden death, particularly after physical activity.

Where is the GYS1 gene located?

Cytogenetic Location: 19q13.3

Molecular Location on chromosome 19: base pairs 48,968,125 to 48,993,353

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

The GYS1 gene is located on the long (q) arm of chromosome 19 at position 13.3.

The GYS1 gene is located on the long (q) arm of chromosome 19 at position 13.3.

More precisely, the GYS1 gene is located from base pair 48,968,125 to base pair 48,993,353 on chromosome 19.

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

Where can I find additional information about GYS1?

You and your healthcare professional may find the following resources about GYS1 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 GYS1 gene or gene products?

  • glycogen [starch] synthase, muscle
  • glycogen synthase 1 (muscle)
  • GSY
  • GYS
  • muscle glycogen synthase
  • muscle glycogen synthase 1

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

What glossary definitions help with understanding GYS1?

cardiac ; cardiac arrest ; enzyme ; fainting ; gene ; glucose ; glycogen ; muscle cells ; simple sugar ; skeletal muscle

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


  • Cameron JM, Levandovskiy V, MacKay N, Utgikar R, Ackerley C, Chiasson D, Halliday W, Raiman J, Robinson BH. Identification of a novel mutation in GYS1 (muscle-specific glycogen synthase) resulting in sudden cardiac death, that is diagnosable from skin fibroblasts. Mol Genet Metab. 2009 Dec;98(4):378-82. doi: 10.1016/j.ymgme.2009.07.012. Epub 2009 Jul 26. (
  • Fredriksson J, Anevski D, Almgren P, Sjögren M, Lyssenko V, Carlson J, Isomaa B, Taskinen MR, Groop L, Orho-Melander M; Botnia Study Group. Variation in GYS1 interacts with exercise and gender to predict cardiovascular mortality. PLoS One. 2007 Mar 14;2(3):e285. (
  • Kollberg G, Tulinius M, Gilljam T, Ostman-Smith I, Forsander G, Jotorp P, Oldfors A, Holme E. Cardiomyopathy and exercise intolerance in muscle glycogen storage disease 0. N Engl J Med. 2007 Oct 11;357(15):1507-14. (
  • NCBI Gene (
  • Orho M, Nikula-Ijäs P, Schalin-Jäntti C, Permutt MA, Groop LC. Isolation and characterization of the human muscle glycogen synthase gene. Diabetes. 1995 Sep;44(9):1099-105. (
  • Sukigara S, Liang WC, Komaki H, Fukuda T, Miyamoto T, Saito T, Saito Y, Nakagawa E, Sugai K, Hayashi YK, Sugie H, Sasaki M, Nishino I. Muscle glycogen storage disease 0 presenting recurrent syncope with weakness and myalgia. Neuromuscul Disord. 2012 Feb;22(2):162-5. doi: 10.1016/j.nmd.2011.08.008. Epub 2011 Sep 29. (


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: January 2014
Published: February 8, 2016