Hereditary fructose intolerance is a disorder in which a person lacks the protein needed to break down fructose. Fructose is a fruit sugar that naturally occurs in the body. Man-made fructose is used as a sweetener in many foods, including baby food and drinks.
Alternative NamesFructosemia; Fructose intolerance; Fructose aldolase B-deficiency; Fructose 1, 6 bisphosphate aldolase deficiency
Causes, incidence, and risk factorsThis condition occurs when the body is missing an enzyme called aldolase B. This substance is needed to break down fructose.
If a person without this substance eats fructose and sucrose (cane or beet sugar, table sugar), complicated chemical changes occur in the body. The body cannot change its energy storage material, glycogen, into glucose. As a result, the blood sugar falls and dangerous substances build up in the liver.
Hereditary fructose intolerance is inherited, which means it is passed down through families. If both parents carry an abnormal gene, each of their children has a 25% chance of being affected. The condition may be as common as 1 in 20,000 people in some European countries.
SymptomsSymptoms can be seen after a baby starts eating food or formula.
The early symptoms of fructose intolerance are similar to those of galactosemia. Later symptoms relate more to liver disease.
Symptoms may include:
Physical examination may show:
Tests that confirm the diagnosis include:
Blood sugar will be low, especially after receiving fructose or sucrose. Uric acid levels will be high.
TreatmentRemoving fructose and sucrose from the diet is an effective treatment for most patients. Complications are treated. For example, some patients can take medication to lower the level of uric acid in their blood and decrease their risk for gout.
Expectations (prognosis)Hereditary fructose intolerance may be mild or severe.
Avoiding fructose and sucrose helps most children with this condition.
A few children with a severe form of the disease will develop severe liver disease. Even removing fructose and sucrose from the diet may not prevent severe liver disease in these children.
How well a person does depends on:
Call your health care provider if your child develops symptoms of this condition after feeding starts. If your child has this condition, experts recommend seeing a Doctor Who specializes in biochemical genetics or metabolism.
PreventionCouples with a family history of fructose intolerance who wish to have a baby may consider genetic counseling.
Most of the damaging effects of the disease can be prevented by sticking to a fructose-free diet.
ReferencesSteinmann B, Santer R, van den Berghe G. Disorders of Fructose Metabolism. In: Fernandes J, Saudubray JM, van den Berghe G, Walter JH, eds. Inborn Metabolic Diseases. 4th ed. New York, NY:Springer;2006:chap 9.
Yes you can
Hereditary fructose intolerance is a rare genetic disorder in which the body lacks the enzyme needed to break down fructose, causing a buildup of toxic byproducts. This can lead to symptoms like nausea, vomiting, abdominal pain, and low blood sugar levels after ingesting fructose. Treatment involves following a strict fructose-free diet.
Fructose intolerance is an inherited disorder passed on to children through their parents' genes. Both the mother and father have the gene that causes the condition, but may not have symptoms of fructose intolerance themselves.
Once diagnosed, fructose intolerance can be successfully treated by eliminating fructose from the diet. Patients usually respond within three to four weeks and can make a complete recovery if fructose-containing foods are avoided.
Carriers of the gene for hereditary fructose intolerance can be identified through DNA analysis. Anyone who is known to carry the disease or who has the disease in his or her family can benefit from genetic counseling.
Urine tests can be used to detect fructose sugar in the urine. Blood tests can also be used to detect hyperbilirubinemia and high levels of liver enzymes in the blood. A liver biopsy may be performed to test for levels of enzymes.
Proximal renal tubular acidosis (type 2) is caused by hereditary diseases, such as Fanconi's syndrome, fructose intolerance, and Lowe's syndrome.
If the condition is not recognized and the diet is not well controlled, death can occur in infants or young children. With a well-controlled diet, the child can develop normally.
Fanconi's syndrome caused secondarily by the genetic diseases galactosemia, glycogen storage disease, hereditary fructose intolerance, and tyrosinemia is prevented by appropriate dietary restrictions to treat the genetic disease.
One person in about 20,000 is born with this disorder. It is reported more frequently in the United States and Northern European countries than in other parts of the world. It occurs with equal frequency in males and females.
Initial symptoms include vomiting, dehydration, and unexplained fever. Other symptoms include extreme thirst and excessive urination and sweating. There will also be a loss of appetite and a failure to grow. Tremors and seizures caused by low.
Short Term EffectsHyperactivitySweet taste in mouthPossible negative/positive aftertasteAllergic reactions (for those with hereditary fructose intolerance)Long Term EffectsOral health issues/Tooth decayObesity and weightSugar withdrawal issuesAddiction to sweet foods and drinks