Summary about Disease
Glycogen Storage Disease Type VII (GSD VII), also known as Tarui disease, is a rare genetic metabolic disorder caused by a deficiency of the enzyme phosphofructokinase (PFK). PFK is crucial for glycolysis, the process that breaks down glucose for energy. This deficiency primarily affects muscle tissue and red blood cells, leading to muscle cramps, fatigue, and hemolytic anemia.
Symptoms
Muscle cramps and pain: Usually brought on by exercise or strenuous activity.
Fatigue: Due to the body's inability to efficiently use glucose for energy.
Hemolytic anemia: Premature destruction of red blood cells, leading to jaundice (yellowing of the skin and eyes), dark urine, and fatigue.
Myoglobinuria: Presence of myoglobin in the urine, causing it to be dark or reddish. This can occur after intense exercise.
Nausea and vomiting: May occur during episodes of muscle cramping.
Elevated creatine kinase (CK) levels: An enzyme released into the blood when muscle damage occurs.
Causes
GSD VII is caused by mutations in the PFKM gene. This gene provides instructions for making the muscle subunit of the phosphofructokinase enzyme. The condition is inherited in an autosomal recessive manner, meaning an individual must inherit two copies of the mutated gene (one from each parent) to be affected.
Medicine Used
There is no specific cure for GSD VII. Treatment focuses on managing symptoms and preventing complications.
Dietary modifications: High-protein, low-carbohydrate diet may help.
Vitamin E supplementation: May help reduce the breakdown of red blood cells.
Management of anemia: Blood transfusions may be necessary in severe cases of hemolytic anemia.
Avoidance of strenuous exercise: To prevent muscle cramps and myoglobinuria.
Is Communicable
No, GSD VII is not communicable. It is a genetic disorder caused by a gene mutation and cannot be spread from person to person.
Precautions
Genetic counseling: For individuals with a family history of GSD VII, genetic counseling is recommended to assess the risk of having affected children.
Dietary management: Follow the dietician recomendations with a high-protein, low-carbohydrate diet to minimize symptoms.
Exercise moderation: Avoid strenuous exercise that can trigger muscle cramps and myoglobinuria.
Monitoring: Regular monitoring of creatine kinase (CK) levels and other blood tests to assess muscle damage and anemia.
How long does an outbreak last?
GSD VII is not an infectious disease, therefore it doesn't have outbreaks. Instead, it is a genetic condition with chronic symptoms. The symptoms duration can vary depending on factors such as activity level and dietary choices. Episodes of muscle cramping and myoglobinuria can last from hours to days.
How is it diagnosed?
Blood tests: Elevated creatine kinase (CK) levels, evidence of hemolytic anemia.
Urine tests: Presence of myoglobin (myoglobinuria).
Muscle biopsy: Analysis of muscle tissue to detect PFK deficiency.
Genetic testing: To identify mutations in the PFKM gene.
Timeline of Symptoms
The onset and severity of symptoms can vary. Some individuals may experience symptoms in early childhood, while others may not develop symptoms until adulthood.
Infancy/Childhood: Some individuals may show delayed motor skills or mild muscle weakness.
Adolescence/Adulthood: Muscle cramps and fatigue typically become more apparent with increased physical activity. Hemolytic anemia may present at any age.
Lifelong: Symptoms are generally chronic and can fluctuate in severity over time.
Important Considerations
Anesthesia: Individuals with GSD VII may be at increased risk for complications during anesthesia. It is important to inform the anesthesiologist about the diagnosis.
Pregnancy: Women with GSD VII should consult with their healthcare provider regarding pregnancy, as the condition can affect energy levels and potentially impact the pregnancy.
Support groups: Joining support groups can provide valuable information and emotional support for individuals with GSD VII and their families.
Medical alert: Wearing a medical alert bracelet or carrying a card that identifies the condition can be helpful in emergency situations.