Summary about Disease
Fructose-1,6-bisphosphatase deficiency (FBPase deficiency) is a rare genetic metabolic disorder that affects the body's ability to produce glucose from non-carbohydrate sources (gluconeogenesis) and to break down glycogen (glycogenolysis). This can lead to low blood sugar (hypoglycemia), a buildup of lactic acid (lactic acidosis), and other metabolic problems, particularly during times of stress, illness, or fasting.
Symptoms
Symptoms typically appear in infancy or early childhood and can include:
Hypoglycemia (low blood sugar)
Lactic acidosis (build-up of lactic acid in the blood)
Hyperventilation (rapid breathing)
Apnea (temporary cessation of breathing)
Lethargy or coma
Seizures
Poor feeding
Vomiting
Abdominal pain
Hepatomegaly (enlarged liver)
Causes
FBPase deficiency is caused by mutations in the FBP1 gene. This gene provides instructions for making the fructose-1,6-bisphosphatase enzyme. This enzyme is crucial for gluconeogenesis, the process by which the liver produces glucose from other sources like amino acids, lactate, and glycerol. The disorder is inherited in an autosomal recessive pattern, meaning that both parents must carry a copy of the mutated gene for their child to be affected.
Medicine Used
There is no specific medication to cure FBPase deficiency. Treatment focuses on managing symptoms and preventing metabolic crises. Common strategies include:
Glucose administration: Intravenous glucose is used during acute episodes of hypoglycemia.
Sodium bicarbonate: Used to correct metabolic acidosis.
Frequent feeding: Providing frequent meals and snacks, especially complex carbohydrates, to prevent hypoglycemia.
Avoidance of fasting: Strict avoidance of prolonged periods without food.
Dietary management: A diet low in fructose and sucrose may be recommended, although dietary restriction is not always necessary.
Is Communicable
No, Fructose-1,6-bisphosphatase deficiency is not communicable. It is a genetic disorder.
Precautions
Avoidance of fasting: Regular meals and snacks are crucial to prevent hypoglycemia.
Prompt treatment of illness: Any illness should be treated aggressively to prevent metabolic decompensation.
Education: Parents and caregivers need to be educated about the signs and symptoms of hypoglycemia and lactic acidosis and how to respond.
Emergency plan: Having a written emergency plan with instructions for treating hypoglycemia is essential.
Medical alert identification: Wearing a medical alert bracelet or necklace can inform medical personnel about the condition in case of an emergency.
Dietary Awareness: Monitoring fructose and sucrose intake may be needed for certain patients.
How long does an outbreak last?
FBPase deficiency is not an "outbreak"-related illness, but rather a chronic, lifelong condition. Episodes of metabolic crisis (hypoglycemia, lactic acidosis) can last from hours to days, depending on the severity and how quickly treatment is initiated.
How is it diagnosed?
Diagnosis typically involves:
Clinical evaluation: Based on symptoms and medical history.
Blood tests: To measure glucose, lactate, and other metabolites, especially during an episode of illness or fasting.
Urine tests: To assess ketone levels.
Enzyme assay: Measuring FBPase activity in liver tissue (rarely done).
Genetic testing: Confirming the diagnosis by identifying mutations in the FBP1 gene.
Timeline of Symptoms
Infancy/Early Childhood: Symptoms typically appear in infancy or early childhood, often triggered by the introduction of fruits or during illness or fasting.
Childhood/Adolescence: With proper management, the frequency and severity of episodes may decrease with age. However, individuals remain at risk throughout their lives, especially during periods of stress, illness, or significant dietary changes.
Adulthood: While less frequent, episodes can still occur in adulthood, particularly during periods of prolonged fasting, pregnancy, or other metabolic stressors.
Important Considerations
Long-term management: FBPase deficiency requires lifelong management to prevent complications.
Individual variability: The severity of the condition can vary significantly from person to person.
Genetic counseling: Genetic counseling is recommended for families with a history of FBPase deficiency.
Multidisciplinary care: Management ideally involves a team of specialists, including a metabolic specialist, a nutritionist, and a geneticist.
Prognosis: With proper management, individuals with FBPase deficiency can live relatively normal lives. However, severe and untreated episodes can lead to neurological damage or death.