Galactose-1-phosphate uridyltransferase is a blood test that measures the level of a substance called GALT, which helps break down milk sugars in your body. Low levels of this substance cause a condition called galactosemia.
Galactosemia screen; GALT; Gal-1-PUT
How the test is performed
Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. This is called a
How the test will feel
When the needle is inserted to draw blood, some infants feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
This is a screening test for
In normal diets, most galactose comes from the breakdown (
Failure to thrive
This can be a serious condition if not treated.
The normal range is 18.5 – 28.5 U/g Hb (units per gram of
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different samples.
What abnormal results mean
An abnormal result suggests
If your child has galactosemia, a genetics specialist should be consulted promptly. The child should immediately be placed on a no-milk diet. This means no breast milk and no animal milk. Soy milk and infant soy formulas are generally used as substitutes.
What the risks are
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
- Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
Early diagnosis is important, because the disease can be treated by removing dairy products from the diet.
Every state requires