From the Guidelines
Glycogen storage disease (GSD) is a group of inherited metabolic disorders characterized by abnormal glycogen metabolism, and the signs and symptoms vary by type, but commonly include hypoglycemia, hepatomegaly, growth retardation, muscle weakness, and exercise intolerance. The initial workup for GSD includes blood glucose monitoring, liver function tests, creatine kinase levels, lactate and uric acid measurements, and liver ultrasound, as well as genetic testing or tissue biopsy (liver or muscle) to identify the specific enzyme deficiency 1. The treatment for GSD focuses on maintaining normal blood glucose levels through frequent feeding, cornstarch therapy (1-2 g/kg every 4-6 hours), and continuous overnight feeding in severe cases, with specific recommendations varying by GSD type 1. Some key features that distinguish GSD III from other types include the absence of hepatomegaly, increased uric acid and lactate, lack of severe ketones, and nephromegaly, as well as the presence of muscle symptoms such as hypotonia, amylopectin-like inclusions, and muscle atrophy 1. The most effective treatment for GSD III is a diet that is higher in complex carbohydrates and protein, with the use of cornstarch therapy to maintain normal blood glucose levels, and regular monitoring of growth, development, and metabolic parameters to prevent complications such as gout, kidney disease, liver adenomas, and cardiomyopathy or skeletal muscle dysfunction 1. In terms of specific dietary recommendations, patients with GSD III should avoid simple sugars and focus on complex carbohydrates, with the addition of protein to offset excessive glycogen storage, and the use of medium chain triglycerides (MCTs) as an alternative source of energy may be beneficial, but requires further investigation 1. Regular monitoring of blood glucose levels, liver function, and other metabolic parameters is essential for long-term management of GSD, and the use of genetic testing and tissue biopsy can help identify the specific enzyme deficiency and guide treatment decisions 1. Some potential complications of GSD include liver adenomas, hepatocellular carcinoma, and end-stage renal disease, and regular monitoring and screening can help prevent or detect these complications early 1. Overall, the management of GSD requires a comprehensive approach that includes dietary management, regular monitoring, and genetic testing to prevent complications and improve quality of life.
From the Research
Signs and Symptoms of Glycogen Storage Disease
- Fasting hypoglycemia
- Hepatomegaly
- Hypertransaminasemia
- Hyperlipidemia
- Exercise intolerance
- Muscle cramps/pain
- Rhabdomyolysis
- Muscle weakness 2
- Hypoglycemia and hepatomegaly as cardinal signs in GSD with liver involvement 3
Initial Workup
- Phenotypic characterization
- Biomarkers
- Imaging
- Genetic testing
- Enzyme activity analysis
- Histology 4
- Clinical manifestations and laboratory test results 3
Treatment
- Dietary management
- Use of uncooked cornstarch to maintain glucose homeostasis 2
- Medically prescribed diets
- Appropriate exercise regimens
- Emergency letters 4
- Enzyme replacement therapy to correct enzyme deficiency in Pompe disease
- SGLT2 inhibitors for neutropenia and neutrophil dysfunction in GSD Ib 4
- Dietary restrictions modulated according to the identified mutation 3
- Pharmacological treatment, physical and supportive therapies, enzyme replacement therapy (ERT) and organ transplantation for both disease manifestations and long-term complications 2