An Overview of Glycogen Storage Diseases

Gastro Sciences | by Dr. Anirban Chatterjee | Published on 29/02/2024

Introduction

If you experience frequent muscle weakness or exercise intolerance, it is important to seek medical attention from healthcare professionals at The Calcutta Medical Research Institute in Kolkata. These symptoms are an indication of glycogen storage diseases (GSDs). It encompasses a group of inherited metabolic disorders determined by anomalies in glycogen metabolism. Glycogen is the body's storage form of glucose playing an important role in maintaining blood sugar levels and offering energy during times of need. However, individuals with GSDs experience difficulties in properly storing and utilizing glycogen, leading to a comprehensive range of symptoms and complications. 

In this blog, you will gain an efficient understanding of glycogen storage diseases and everything related to glycogen storage diseases. However, kindly understand that this write-up is for informative purposes only, we do not encourage overlooking the doctor’s consultation. If you are facing any issues or problems, you can consult with the best gastroenterologist in Kolkata to learn more about the disease and your condition.

What is Glycogen Storage Disease?

Glycogen storage diseases are genetic disorders caused by enzyme deficiencies involved in glycogen synthesis or breakdown. These insufficiencies harm the natural process of glycogen metabolism, leading to abnormal glycogen accumulation or depletion in various tissues throughout the body. Depending on the particular enzyme deficiency, varied types of glycogen storage diseases have unique clinical features and severity. As per one study, GSDs happen in about one in one thousand births. This condition targets both males and females equally. 

What are the types of glycogen storage diseases?

Several types of glycogen storage diseases are classified depending on the enzyme insufficiency for the disorder:

• Glycogen Storage Disease Type I (von Gierke Disease)
• Glycogen Storage Disease Type II (Pompe Disease)
• Glycogen Storage Disease Type III (Cori Disease)
• Glycogen Storage Disease Type IV (Andersen Disease)
• Glycogen Storage Disease Type V (McArdle Disease)
• Glycogen Storage Disease Type VI (Hers Disease)
• Glycogen Storage Disease Type VII (Tarui Disease)
• Glycogen Storage Disease Type VIII (Phosphorylase Kinase Deficiency)

What are the glycogen storage disease symptoms?

Glycogen storage disease symptoms vary from person to person. Hence, it is vital to understand the common symptoms that can occur. Here are some of them:

• Hypoglycemia (low blood sugar)
• Hepatomegaly (enlarged liver)
• Growth retardation
• Muscle weakness
• Exercise intolerance
• Cardiomyopathy (heart muscle disease)
• Hypotonia (weak muscle tone)
• Hyperlipidemia (high blood lipid levels)
• Renal involvement

What are glycogen storage disease causes?

GSDs are inherited in an autosomal recessive pattern, meaning both parents should carry a mutated gene for a child to inherit the disorder. The mutations affect genes encoding enzymes involved in glycogen metabolism causing enzyme deficiencies and subsequent metabolic anomalies. Environmental factors may also influence the severity and growth of GSDs.

How is glycogen storage disease diagnosed?

Diagnosing GSDs typically involves a combination of clinical evaluation, biochemical testing, genetic testing, and imaging studies. Blood tests help in identifying abnormal levels of glucose, lactate, and liver enzymes. Molecular genetic testing determines particular gene mutations linked to varied types of GSDs. Imaging studies such as ultrasound or MRI are involved to evaluate organ involvement and monitor disease progression.

What are the options available for glycogen storage disease treatment?

Management of GSDs focuses on alleviating symptoms, preventing complications, and improving quality of life. Treatment strategies may include:

• Dietary modifications include controlled intake of carbohydrates, frequent meals, and supplementation with uncooked cornstarch to maintain blood glucose levels. 
• Medications: Some GSDs may require medications to manage specific symptoms or complications, such as lipid-lowering drugs or growth hormone therapy.
• Monitoring and surveillance: Regular monitoring of blood glucose, liver function, cardiac function, and growth is essential to detect and manage complications early.
• Liver transplantation: In severe cases of GSD Type I or IV with progressive liver disease, liver transplantation may be considered to improve long-term outcomes.

Conclusion

Glycogen storage diseases represent a diverse group of genetic disorders posing significant challenges in diagnosis and management. Despite advances in understanding the underlying molecular mechanisms, treatment options remain restricted, emphasizing the requirement for continued research and therapeutic innovations. Through comprehensive medical care, individuals with GSDs can accomplish improved outcomes and quality of life, highlighting the significance of multidisciplinary approaches in managing these complex conditions.

Faq -

 

Which organ in the body stores excess sugar as glycogen?

The liver is an organ in the body that stores excess sugar as glycogen. If the levels of blood sugar are high, then the liver transforms into glycogen for storage. 

Why is glucose stored as glycogen?

Glucose is stored in the liver as glycogen including muscles to offer a steady supply of energy source for the body. The conversion of glycogen consents to the blood sugar levels regulation, ensuring a regular energy supply during fasting periods or when there is an increased demand for energy.