GALT (Galactose-1-Phosphate Uridylyltransferase) Gene Allele 1 — Whole Blood, Qualitative
A qualitative blood test that analyzes a selected allele of the GALT gene, which is associated with classic galactosemia.
["This test identifies a selected GALT gene allele and may help assess the risk of GALT-related galactosemia."]
Key facts at a glance
- LOINC
- 42940-7
- Short code
- GALT allele 1 Bld Ql
- Synonyms
- GALT allele 1 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 is a genetic test performed on whole blood to examine a selected allele, called allele 1, of the GALT gene. Changes in this gene can affect the ability to process galactose, a type of sugar found in milk and some other foods.
Why might I need this test?
This test may be ordered when an infant or child has symptoms suggesting classic galactosemia, such as vomiting, poor feeding, jaundice, liver problems, or failure to thrive. It may also be used when there is a family history of the condition or a related abnormal screening result.
How is the test performed?
A blood sample is collected and analyzed in a laboratory to determine whether the selected GALT allele is present. The result is qualitative, meaning that the allele is reported as detected or not detected rather than as a measured concentration.
How do I prepare for the test?
Fasting is usually not required for this blood test. Follow any instructions provided by the ordering laboratory, and tell the healthcare team about any medicines, supplements, or recent blood transfusions.
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.
Detecting the selected allele may indicate a genetic change associated with GALT-related galactosemia, but the clinical meaning depends on how that allele is classified and on other genetic or laboratory findings. A detected result does not by itself establish that a person has the disorder, and a not-detected result cannot exclude all GALT variants. Results should be interpreted by a qualified healthcare professional, especially in a newborn or a child with symptoms.
Short name
GALT allele 1 genetic test
Frequently asked questions
What does this GALT test tell me?
Does a detected result mean I have galactosemia?
Is fasting required before this test?
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