HFI Laboratory at Boston University

How is HFI diagnosed?

The only definitive way to ascertain if one is suffering from HFI is to have one of two tests:

  • 1) An enzymatic assay to determine aldolase activity. The aldolase is obtained from patient liver tissue in an invasive surgical procedure called a liver biopsy.
  • 2) A fructose tolerance test. Fructose is injected intravenously under controlled conditions where acute glucose, fructose, and phosphate levels are monitored.

HOWEVER, both tests represent considerable risk, especially in a newborn.

A newer, non-invasive DNA test is readily becoming more available. While the DNA test is not diagnostic because negative results do not guarantee that one does not have HFI, positive results, along with clinical symptoms, are strong indicators of disease. A presumptive diagnosis can be made.

A Word of CAUTION!

An unreliable method is the H2 breath test.  The hydrogen breath test is a safe and noninvasive procedure that may diagnose fructose malabsorption.  Following ingestion of fructose, the hydrogen concentration of the patient’s breath is measured at various time intervals.  An increase above baseline hydrogen concentration suggests fructose malabsorption.  NOTE: This test has not been shown to be an effective means of diagnosing fructose intolerance.  Click here to for more information regarding fructose intolerance and fructose malabsorbance.


For more information on getting tested click here

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