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Diagnostic Services

Genetics Lab


Galactosemia Enyzme Assay

Galactosemia is an inherited disorder of galactose metabolism. Individuals with galactosemia are unable to break down galactose, a sugar found primarily in dairy products and some vegetables and legumes. Galactosemia is caused by a deficiency in the enzyme galactose-1-phosphate uridyltransferase, and individuals with galactosemia have mutations in the GALT gene. They also have elevated galactose-1-phosphate, a metabolite of galactose metabolism. Galactosemia affects about 1/10000 individuals and is included in the Washington State newborn screening program.

Test Name: Galactose-1-phosphate Uridyl Transferase, Quantitative
Test Code:
Test Description:
Quantitative measurement of galactose-1-phosphate uridyltransferase in erythrocytes.
This test is used to diagnose galactosemia in a symptomatic individual. It can also be helpful for determining carrier status.
Related Tests: Galactose-1-phosphate, Quantitative  
This test is used to monitor known galactosemia patients

Galactosemia (8 Mutations)  
This test is used to provide additional information regarding diagnosed patients, provide carrier testing for at-risk family members or carrier testing for the general population

Galactosemia DNA 1 Mutation  
This test is used to provide carrier testing or prenatal testing for at-risk family members. Mutations must be known.

Clinical Links: Galactosemia GeneReview
Set up Mon - Fri
Turnaround Time:
2-5 days
Fluorometric enzyme assay
Reference Range:
19-29 U/G Hemoglobin
Consent Form:
Sample Requirements: Type
Whole blood: 2-5 mL ACD A or B (yellow), heparin (green) or EDTA (purple) tube.
No gel separator tubes

Do not spin. Keep refrigerated.

Overnight shipping with a cold pack. Sample MUST be received within 24 hours of collection
Samples Received:
Mon – Fri 8:00 am – 5:00 pm PST
Special Considerations:
Method is affected by age of sample, improper storage/shipping, recent transfusions. Clotted samples are unacceptable.
Please e-mail Client Services or call at 206-987-2617 with any billing questions
CPT Code:
Please e-mail Client Services or call at 206-987-2617 with any billing questions