Galactose-1-Phosphate Uridyltransferase
Alternate Names : Gal-1-PUT, Galactosemia Screen, GALT
Definition This is a blood test that measures the level of GALT, an enzyme involved in breakdown of milk sugars (lactose/galactose).
Why is the Test Performed?
This is a screening test for galactosemia.
In normal diets, the major source of galactose is in the metabolism of lactose. The major source of dietary lactose is milk and dairy products. In most people, galactose is converted to glucose by a series of chemical reactions. Each chemical reaction is catalyzed by an enzyme.
About 1 out of 65,000 newborns has a deficiency of the GALT enzyme (deficiencies of the other enzymes are much less common). As a consequence, galactose accumulates in the blood (galactosemia) and tissues because it cannot be metabolized.
Because milk is an important part of the diet of most newborns, these infants develop fluid imbalance and failure to thrive. Continued use of galactose can also result in cataracts, jaundice, liver enlargement, cirrhosis, and mental retardation.
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