Final answer:
Hereditary fructose intolerance is a condition where the lack of the enzyme aldolase-B leads to the accumulation of fructose-1-phosphate, causing symptoms like hypoglycemia. Individuals must avoid fructose, sucrose, and sorbitol in their diet to prevent these effects.
Step-by-step explanation:
Hereditary Fructose Intolerance
Hereditary fructose intolerance (HFI) is a metabolic disorder caused by a deficiency of the enzyme aldolase-B, which is necessary for the proper metabolism of fructose. In individuals with HFI, the ingestion of fructose-rich foods, such as fruits, honey, and table sugar (sucrose), leads to an accumulation of fructose-1-phosphate because it cannot be broken down by the impaired enzyme. This build-up of fructose-1-phosphate in the liver, kidneys, and small intestine interferes with glucose production and causes symptoms of low blood sugar (hypoglycemia), abdominal pain, and vomiting.
Unlike essential fructosuria, which is characterized by the excretion of fructose in the urine due to the lack of the enzyme fructokinase, HFI involves serious metabolic consequences. With the inability to properly utilize fructose, affected individuals must maintain a fructose-free diet. This strict dietary management prevents the harmful effects of fructose accumulation.
It is also worth noting that similar to lactose intolerance, where individuals lack the enzyme lactase needed to digest lactose in milk, people with HFI have to avoid intake of not just fructose, but also sucrose and sorbitol as they are metabolized into fructose. Close monitoring of diet and potential fructose sources is essential in managing hereditary fructose intolerance.