Hereditary fructose intolerance is an illness where the enzyme aldolase B, which breaks down the fructose in the liver, intestines and kidneys, does not function adequately, causing an accumulation of fructose-1-phosphate in the cells that should metabolize it. This accumulation becomes toxic, and eventually causes hepatomegaly, cirrhosis, renal failure, among other disorders.
Fructose is a sugar that is found in many foods; as such it is found in fruits and numerous vegetables, associated with glucose as a sucrose or common sugar (fructose + glucose) or it can be synthesized in the body from sorbitol (a commonly used sweetener), being the latter another source of fructose.
Artificial fructose is used as a sweetener in many foods, including foods and drinks for babies.
Fructose intolerance is a autosomal recessive disorder that is transmitted from parents to children, i.e., the two genes inherited from both mother and father and needed to synthesize the protein, are defective.
The disorder is considered a rare disease since it has a low incidence in the population. It affects a limited number of persons, 1 in 20,000.