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Galactose-1-Phosphate Uridyltransferase (GALT) Enzyme Activity

Published: July 27, 2026Updated: August 25, 2026

GALT enzyme activity measures the function of the GALT enzyme, which is crucial for galactose metabolism. Deficiency in this enzyme can lead to galactosemia.

Quick summary

GALT enzyme activity assesses galactose metabolism efficiency and detects galactosemia.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
U/gHb
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
Roche ALT, Abbott ALT, Siemens ALT, IFCC ALT
interpretation: {"text":"GALT enzyme activity below 7 U/gHb may indicate galactosemia or other metabolic disorders.","label":"Low"}; {"text":"GALT enzyme activity within the range of 7–21 U/gHb is considered normal.","label":"Normal"}

The GALT enzyme is essential for converting galactose to glucose, a critical process in carbohydrate metabolism. Measuring GALT enzyme activity helps evaluate the body's ability to process galactose.

A deficiency in GALT enzyme activity can lead to the accumulation of toxic galactose metabolites, causing galactosemia, a rare but serious genetic disorder.

The reference range for GALT enzyme activity is typically between 7–21 U/gHb. Values below this range may indicate galactosemia or other metabolic disorders.

Frequently asked questions

What are the symptoms of galactosemia?
Symptoms include jaundice, vomiting, lethargy, and failure to thrive in infants. If untreated, it can lead to severe complications such as liver damage and intellectual disability.
How is galactosemia treated?
Treatment primarily involves a strict diet free from galactose and lactose, which helps prevent the accumulation of toxic metabolites.
  1. 1
    National Institutes of Health (NIH) on GalactosemiaSource
  2. 2
    MedlinePlus on GALT EnzymeSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy