About the disease

Question 1

Gentics of HFI

Answer 1

• Due to the mutation of enzyme aldolase B located on chromosome 9q22.3
• Mutational aberrations include missense mutations, deletions, frameshift mutations and mutations at splicing sites

Question 2

Inheritance of HFI

Answer 2

• Autosomal recessive disease
• 25% (1 in 4) chance to have a child who has the heredtary fructose intolerance

Question 3

Pathogenesis of HFI

Answer 3

• Aldolase B (fructose-1,6-bisphosphate aldolase) enzyme acts on fructose 1- phosphate (F-1P)
• It forms dihydroxyacetone phosphate (DHAP) and glyceraldehyde (GAH)
• In absence of aldolase B enzyme, F-1P accmulates rapidly in liver, kidney and small intestine
• result in metabolic inhibition of glycogen and glucose
• cause severe hypoglycemic condition (low sugar in the blood)

Question 4

Clinical symptoms of HFI

Answer 4

abdominal pain, vomiting, weakness, convulsions, sleepiness, irritability, yellow skin or whites of the eyes

Question 5

Diagnosis of HFI

Answer 5

• Liver biopsy- to detect catalytic activity of aldolase B
• Fructose tolerance test- patient’s response to intravenous fructose
  injection is carefully monitored
• PCR test- detect mutated aldolase-B gene
• Fructose detection excreted in urine

Question 6

Treatment for HFI

Answer 6

• Excluding fructose, sucrose and sorbitol from the diet

Question 7

Prognosis of HFI

Answer 7

• Early diagnosis is important to lead a normal life if the patient adopt a fructose-free diet
• If left untreated, condition can lead to permanent physical harm, including serious liver and kidney damage
• HFI may be mild or severe

Question 8

Other names for hereditary fructose intolerance

Answer 8

• ALDOB deficiency
• Aldolase B deficiency
• Fructose aldolase B deficiency
• Fructose intolerance
• Fructose-1,6-biphosphate aldolase deficiency
• Fructose-1-phosphate aldolase deficiency
• Fructosemia