Summary about Disease
Glycogen storage disease type VI (GSD VI), also known as Hers disease, is a genetic disorder that affects the liver's ability to break down glycogen. Glycogen is the stored form of glucose (sugar), which the body uses for energy. In GSD VI, a deficiency in the enzyme liver glycogen phosphorylase prevents the liver from properly releasing glucose into the bloodstream when needed, leading to a buildup of glycogen in the liver. It is typically a milder form of glycogen storage disease compared to other types.
Symptoms
Symptoms of GSD VI are typically mild and may include:
Enlarged liver (hepatomegaly)
Growth delay (especially in childhood)
Mildly low blood sugar (hypoglycemia), particularly during fasting
Elevated liver enzymes
Fatigue
Abdominal distension Some individuals may have no noticeable symptoms.
Causes
GSD VI is caused by mutations in the PYGL gene. This gene provides instructions for making the liver glycogen phosphorylase enzyme. Mutations in *PYGL* lead to a deficiency or malfunction of this enzyme, impairing the breakdown of glycogen in the liver. It is inherited in an autosomal recessive pattern, meaning that an affected individual must inherit two copies of the mutated gene (one from each parent).
Medicine Used
There is no specific cure for GSD VI, but management focuses on controlling symptoms and preventing complications. Treatment strategies may include:
Frequent meals and snacks: Eating regularly, especially complex carbohydrates, helps to maintain stable blood sugar levels.
Uncooked cornstarch: Providing uncooked cornstarch before bedtime, or even during the day, allows for the slow release of glucose during the night, preventing hypoglycemia.
High-protein diet: A high-protein diet can help maintain blood sugar levels.
Monitoring: Regular monitoring of blood glucose levels and liver function is important.
Is Communicable
No, GSD VI is not communicable. It is a genetic disorder and cannot be spread from person to person.
Precautions
Precautions for individuals with GSD VI include:
Adherence to dietary recommendations: Following a consistent meal schedule and dietary plan is crucial for maintaining stable blood sugar.
Avoiding prolonged fasting: Fasting should be avoided to prevent hypoglycemia.
Regular monitoring: Regular medical follow-up and monitoring of blood glucose and liver function.
Medical alert: Wearing a medical alert bracelet or carrying identification that indicates the condition and emergency contact information.
How long does an outbreak last?
GSD VI is not an infectious disease, so the term "outbreak" is not applicable. It is a chronic condition that requires lifelong management. The severity of symptoms can vary over time, but the underlying genetic defect is always present.
How is it diagnosed?
Diagnosis of GSD VI typically involves:
Clinical evaluation: Assessment of symptoms, medical history, and family history.
Blood tests: Measurement of blood glucose levels, liver enzymes, and other relevant markers.
Liver biopsy: A liver biopsy may be performed to assess glycogen levels and enzyme activity in the liver tissue.
Genetic testing: Genetic testing of the PYGL gene can confirm the diagnosis by identifying mutations.
Timeline of Symptoms
Symptoms of GSD VI can appear in infancy or early childhood, but some individuals may not be diagnosed until later in life due to the mild nature of the condition.
Infancy/Early Childhood: Enlarged liver, growth delay, mild hypoglycemia.
Childhood/Adolescence: Symptoms may remain stable or improve with age and dietary management.
Adulthood: Some individuals may continue to experience mild symptoms, while others may be asymptomatic.
Important Considerations
Genetic counseling: Genetic counseling is recommended for families with a history of GSD VI to assess the risk of recurrence in future pregnancies.
Individualized management: Treatment should be tailored to the individual's specific needs and symptoms.
Long-term monitoring: Regular follow-up with a healthcare provider is important for monitoring liver function and managing potential complications.
Exercise: Exercise is often well-tolerated, but it's important to monitor blood glucose levels and adjust dietary intake as needed.