Fructose biphosphatase deficiency, also known as fructose-1,6-bisphosphatase deficiency (FBPase or FBP1 deficiency), is a rare inborn error of carbohydrate metabolism characterized by the deficiency of the fructose-1,6-bisphosphatase enzyme. It is an autosomal recessive disorder caused by mutations in the FBP1 gene.
Fructose-1,6-bisphosphatase is an enzyme involved in gluconeogenesis, a process that converts non-carbohydrate sources, like amino acids and lipids, into glucose. This enzyme plays a crucial role in maintaining stable blood glucose levels when fasting or during prolonged exercise, as it helps break down stored glycogen in the liver and muscles into glucose. However, individuals with fructose biphosphatase deficiency lack sufficient levels of this enzyme, which leads to impaired gluconeogenesis and subsequent low blood glucose levels (hypoglycemia).
Symptoms of fructose biphosphatase deficiency typically appear during infancy or early childhood and can include recurrent episodes of hypoglycemia, lethargy, irritability, rapid breathing (hyperventilation), seizures, and failure to thrive. These symptoms often become more severe during periods of fasting or illness.
Treatment of fructose biphosphatase deficiency primarily focuses on preventing hypoglycemic episodes through careful dietary management. This involves avoiding sources of fructose and sucrose, using alternative carbohydrates as energy sources, frequent meals, and close monitoring of blood glucose levels. In some cases, medications like diazoxide or glucagon may be prescribed to help stabilize blood sugar levels.
Early diagnosis and management of fructose biphosphatase deficiency are essential to prevent complications and ensure optimal growth
