What is Hereditary Fructose Intolerance (HFI)?

Hereditary Fructose Intolerance (HFI) is a rare genetic disease in which fructose can’t be properly metabolised in the body. Affected person gets bad abdominal reaction (bloating, diarrhea, generalized malaise) after eating fructose-containing foods. HFI is an autosomal recessive disorder of fructose metabolism, due to a deficiency of fructose-1-phosphate aldolase - an enzyme, which converts fructose into glucose in the liver. Incidence of HFI is estimated at 1 / 22-58,000 (1).

HFI should be differed from fructose malabsorption (dietary fructose intolerance - DFI).

Patophysiology of HFI

Absorbed fructose is normally converted into fructose-1-phosphate, and further into glucose in the liver. In HFI, fructose-1-phosphate, due to lack of enzyme fructose-1-phosphate aldolase, can’t be converted into glucose, so it accumulates in liver, intestine, and kidneys, and inhibits glucose synthesis, thus causing hypoglycemia. Prolonged fructose ingestion in infants may cause hepatic or renal failure and death.