Glycogen Storage Disease Type III (GSDIII) Information

Also known as Cori disease, Forbes disease, AGL deficiency, glycogen storage disease type 3 (GSD3)

What is it?

Glycogen storage disease type III (GSDIII) is a rare genetic disorder that causes glycogen (a type of sugar that the body uses for energy) to build up in the liver and muscles, preventing them from working properly.

What Causes It?

GSDIII is caused by mutations in the AGL gene. The AGL gene provides the instructions for an enzyme that helps break down glycogen. When glycogen is not broken down completely, it can cause damage to the liver, muscles, and other organs and tissues in the body.¹

What Are Some Common Symptoms?¹

Chronic liver disease
Decreased muscle tone
High concentration of fats in the blood
Larger liver than normal
Low blood sugar
Muscle weakness
Poor growth (failure to thrive)
Heart complications

How Many People Have It?

About 10,000 people worldwide have GSDIII.

Learn how mRNA therapies have the potential to address conditions like GSDIII

Glycogen storage disease type III. MedlinePlus website. https://medlineplus.gov/genetics/condition/glycogen-storage-disease-type-iii/. Published May 28, 2019. Accessed June 5, 2019.

Intended for U.S. audiences only

Participate in GSDIII Research

To talk to someone and get more information about Ultragenyx clinical trials and research, email [email protected]

Research plays a critical part in advancing science and treatments. Volunteers who participate in this research are essential. Future therapies would not be possible without them. Participating in clinical trials, interviews, observational studies, and disease monitoring programs help to drive research, treatment development, and disease education. It is also a way to advocate for yourself and your community.

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GSDIII Patient Advocacy Groups*

*These organizations are an incomplete listing of rare disease advocacy groups and are not controlled by, endorsed by, or affiliated with Ultragenyx Pharmaceutical Inc. The list is meant for informational purposes only and is not intended to replace your healthcare professional’s medical advice. Ask your doctor or nurse any questions you may have about your disease or treatment plan. If you would like to have your group added to the list, please contact [email protected].

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