• Disease Overview
  • Synonyms
  • Subdivisions
  • Signs & Symptoms
  • Causes
  • Affected Populations
  • Disorders with Similar Symptoms
  • Diagnosis
  • Standard Therapies
  • Clinical Trials and Studies
  • References
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  • Complete Report

Glycogen Storage Disease Type I


Last updated: December 23, 2019
Years published: 1987, 1990, 1991, 1998, 2006, 2007, 2012, 2016, 2019


NORD gratefully acknowledges Deeksha Bali, PhD, Professor, Division of Medical genetics, Department of Pediatrics, Duke Health; Co-Director, Biochemical Genetics Laboratories, Duke University Health System, and Yuan-Tsong Chen, MD, PhD, Professor, Division of Medical Genetics, Department of Pediatrics, Duke Medicine; Distinguished Research Fellow, Academia Sinica Institute of Biomedical Sciences, Taiwan for assistance in the preparation of this report.

Disease Overview

Glycogen storage diseases are a group of disorders in which stored glycogen cannot be metabolized into glucose to supply energy and to maintain steady blood glucose levels for the body. Type I glycogen storage disease is inherited as an autosomal recessive genetic disorder. Glycogen storage disease type I (GSDI) is characterized by accumulation of excessive glycogen and fat in the liver and kidneys that can result in an enlarged liver and kidneys and growth retardation leading to short stature. GSDI is associated with abnormalities (mutations) in the G6PC gene (GSDIA) or SLC37A4 gene (GSDIB). These mutations result in enzyme deficiencies that block glycogen breakdown in affected organs causing excess amounts of glycogen and fat accumulation in the body tissues and low levels of circulating glucose in the blood. The enzyme deficiency also results in an imbalance or excessive accumulation of other metabolites, especially lactates, uric acid and fats like lipids and triglycerides.

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  • glucose-6-phosphatase deficiency
  • glucose-6-phosphate transport defect
  • glycogenosis type I
  • GSDI
  • Von Gierke disease
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  • glycogen storage disease type IA
  • glycogen storage disease type IB
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Signs & Symptoms

The primary symptom of GSDI in infancy is a low blood sugar level (hypoglycemia). Symptoms of GSDI usually begin at three to four months of age and include enlargement of the liver (hepatomegaly), kidney (nephromegaly), elevated levels of lactate, uric acid and lipids (both total lipids and triglycerides), and possible seizures caused due to repeated episodes of hypoglycemia. Continued low blood sugar can lead to delayed growth and development and muscle weakness. Affected children typically have doll-like faces with fat cheeks, relatively thin extremities, short stature, and protuberant abdomen.

High lipid levels can lead to the formation of fatty skin growths called xanthomas. Other conditions that can be associated with untreated GSD1 include; osteoporosis, delayed puberty, gout (arthritis caused by accumulation of uric acid), kidney disease, pulmonary hypertension (high blood pressure in the arteries that supply the lungs), hepatic adenoma (benign liver tumors), polycystic ovaries in females, an inflammation of the pancreas (pancreatitis), diarrhea and changes in brain function due to repeated episodes of hypoglycemia.

Impaired platelet function can lead to a bleeding tendency with frequent nose bleeds (epistaxis). In general GSD type Ib patients have similar clinical manifestations as type Ia patients, but in addition to the above mentioned manifestations, GSDIb is also associated with impaired neutrophil and monocyte function as well as chronic neutropenia after the first few years of life, all of which result in recurrent bacterial infections and oral and intestinal mucosal ulcers.

Early diagnosis and effective treatment can result in normal growth and puberty and many affected individuals live into adulthood and enjoy normal life activities. Many female patients have had successful pregnancies and childbirth.

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Type I glycogen storage disease is associated with abnormalities in two genes. Mutations in the G6PC gene result in a deficiency in the glucose-6-phosphatase (G6Pase) enzyme and account for approximately 80% of GSDI. This type of GSDI is termed glycogen storage disease type Ia. Mutations in the SLC37A4 gene result in a deficiency in the glucose-6-phosphatase translocase enzyme (transporter deficiency) and account for approximately 20% of GSDI. This type of GSDI is termed glycogen storage disease type Ib. Both these enzyme deficiencies cause excess amounts of glycogen along with fats to be stored in the body tissues.

Type I glycogen storage disease is inherited as an autosomal recessive genetic disorder. Recessive genetic disorders occur when an individual inherits a non-working gene from each parent. If an individual receives one working gene and one non-working gene for the disease, the person will be a carrier for the disease, but usually will not show symptoms. The risk for two carrier parents to both pass the non-working gene and, therefore, have an affected child is 25% with each pregnancy. The risk to have a child who is a carrier, like the parents, is 50% with each pregnancy. The chance for a child to receive working genes from both parents is 25%. The risk is the same for males and females.

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Affected populations

Type I glycogen storage disease occurs in approximately 1 in 100,000 births. The prevalence of GSDI in Ashkenazi Jews is approximately 1 in 20,000. This condition affects males and females in equal numbers in any given population group.

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GSD type I is diagnosed by laboratory tests that indicate abnormal levels of glucose, lactate, uric acid, triglycerides and cholesterol. Molecular genetic testing for the G6PC and SLC37A4 genes is available to confirm a diagnosis. Molecular genetic testing can also be used for carrier testing and prenatal diagnosis. Liver biopsy can also be used to prove specific enzyme deficiency for GSD Ia.

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Standard Therapies

GSDI is treated with a special diet in order to maintain normal glucose levels, prevent hypoglycemia and maximize growth and development. Frequent small servings of carbohydrates must be maintained during the day and night throughout the life. Calcium, vitamin D and iron supplements maybe recommended to avoid deficits. Frequent feedings of uncooked cornstarch are used to maintain and improve blood levels of glucose. Allopurinol, a drug capable of reducing the level of uric acid in the blood, may be useful to control the symptoms of gout-like arthritis during the adolescent years. Medications maybe prescribed to lower lipid levels and prevent and/or treat kidney disease. Human granulocyte colony stimulating factor (GCSF) may be used to treat recurrent infections in GSD type Ib patients. Liver tumors (adenomas) can be treated with minor surgery or a procedure in which adenomas are ablated using heat and current (radiofrequency ablation). Kidney and/or liver transplantation are sometimes considered if other therapies are unsuccessful or where liver adenomas keep growing.

Individuals with GSDI should be monitored at least annually with kidney and liver ultrasound and routine blood work specifically used for monitoring GSD patients.

Genetic counseling is recommended for affected individuals and their families.

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Clinical Trials and Studies

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov . All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the National Institutes of Health (NIH) in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]

Some current clinical trials also are posted on the following page on the NORD website:

For information about clinical trials sponsored by private sources, contact:

For information about clinical trials conducted in Europe, contact:

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Chen YT, Bali DS. Prenatal Diagnosis of Disorders of Carbohydrate Metabolism. In: Milunsky A, Milunsky J, eds. Genetic disorders and the fetus – diagnosis, prevention, and treatment. 6th ed. West Sussex, UK: Wiley-Blackwell; 2009.

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Austin SL, El-Gharbawy AH, Kasturi VG, James A, Kishnani PS. Menorrhagia in patients with type I glycogen storage disease. Obstet Gynecol 2013;122:1246–1254.

Dagli AI, Lee PJ, Correia CE, et al. Pregnancy in glycogen storage disease type Ib: gestational care and report of first successful deliveries. J Inherit Metab Dis. 2010;Dec 33 Suppl 3:S151-7.

Chou JY, Mansfield BC. Mutations in the glucose-6-phosphatase-alpha (G6PC) gene that cause type Ia glycogen storage disease. Hum Mutat. 2008;29:921-30.

Franco LM, Krishnamurthy V, Bali D, et al. Hepatocellular carcinoma in glycogen storage disease type Ia: a case series. J Inherit Metab Dis. 2005;28:153-62.

Lewis R, Scrutton M, Lee P, Standen GR, Murphy DJ. Antenatal and Intrapartum care of a pregnant woman with glycogen storage disease type 1a. Eur J Obstet Gynecol Reprod Biol. 2005;118:111-2.

Ekstein J, Rubin BY, Anderson, et al. Mutation frequencies for glycogen storage disease in the Ashkenazi Jewish Population. Am J Med Genet A. 2004;129:162-4.

Melis D, Parenti G, Della Casa R, et al. Brain Damage in glycogen storage disease type I. J Pediatr. 2004;144:637-42.

Rake JP, Visser G, Labrune, et al. Guidelines for management of glycogen storage disease type I-European study on glycogen storage disease type I (ESGSD I). Eur J Pediatr. 2002b;161:112-9.

Rake JP Visser G, Labrune P, et al. Glycogen storage disease type I: diagnosis, management, clinical course and outcome. Results of the European study on glycogen storage disease type I (EGGSD I). Eur J Pediat. 2002a;161:20-34.

Chou JY, Matern D, Mansfield, et al. Type I glycogen Storage diseases: disorders of the glucose-6-Phosphatase complex. Curr Mol Med. 2002;2:121-43.

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Visser G, Rake JP, Labrune P, et al. Consensus guidelines for management of glycogen storage disease type 1b. Results of the European study on glycogen storage disease type I. Eur J Pediatr. 2002;161:120-3.

Weinstein DA and Wolfsdorf JI. Effect of continuous gucose therapy with uncooked cornstarch on the long-term clinical course of type 1a glycogen storage disease. Eur J Pediatr 2002;161:35-9.

Janecke AR, Mayatepek E, and Utermann G. Molecular genetics of type I glycogen storage disease. Mol Genet Metab. 2001;73:117-25.

Viser G, Rake JP, Fernandes, et al. Neutropenia, neutrophil dysfunction, and inflammatory bowel disease in glycogen storage disease type 1b: results of the European study on glycogen storage disease type I. J Pediatr. 2000;137:187-91.

Chen YT, Bazarre CH, Lee MM, et al. Type I glycogen storage disease: nine years of management with corn starch. Eur J Pediatr. 1993;152:56-9.

Bali DS, Chen YT, Austin S, et al. Glycogen Storage Disease Type I. 2006 Apr 19 [Updated 2016 Aug 25]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2019. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1312/ Accessed October 21, 2019.

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