Galactose-1-phosphate Uridylyltransferase (GALT) Gene Allele 2, Whole Blood — Qualitative
This qualitative genetic test checks whole blood for a specific variant, or allele 2, of the GALT gene associated with galactosemia.
["The result identifies whether a specific GALT gene variant is present, but it must be interpreted with other genetic and clinical findings."]
Key facts at a glance
- LOINC
- 42941-5
- Short code
- GALT allele 2 Bld Ql
- Synonyms
- GALT allele 2 Bld Ql
- Category
- liver
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 7
- Ref high
- 56
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- molgen
- CPT
- 84484
- SNOMED
- 302773008
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test looks for allele 2 of the GALT gene in DNA obtained from a whole-blood sample. GALT provides instructions for making galactose-1-phosphate uridylyltransferase, an enzyme needed to process galactose, a type of sugar.
Why might I need this test?
This test may be ordered when a newborn screening result, symptoms, or family history suggest classic galactosemia. It can also be used to assess certain parent or relative carrier-risk scenarios when the laboratory offers targeted genetic testing.
How is the test performed?
A blood sample is collected, and laboratory staff analyze the DNA for the specified GALT variant. The report should state whether the variant was detected and include an appropriate clinical interpretation.
How do I prepare for the test?
Special preparation is usually not required for a whole-blood genetic test, and fasting is generally unnecessary. Follow the laboratory's collection instructions and tell the care team if you have had a bone marrow transplant or received a recent blood transfusion, as these can affect the sample.
Reference range
Adult males: 7-56 U/L; Adult females: 7-43 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Detection of this GALT variant may indicate a genetic change that can reduce the enzyme's ability to process galactose. A result showing that the variant was not detected does not exclude other GALT variants or other causes of galactosemia. A genetic counselor or treating clinician should interpret the result together with enzyme activity, newborn screening, symptoms, and other relevant testing.
Short name
GALT allele 2 test
Frequently asked questions
Does a detected GALT allele 2 result mean I have galactosemia?
Can this test determine whether I am a carrier?
Will the result be affected by eating dairy or other sources of galactose?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy