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22652 Galactose-1-Phosphate Uridyltransferase Gput (GALT)

Galactose-1-Phosphate Uridyltransferase Gput (GALT)
Test Code: MISC
Synonyms/Keywords
​Ref Lab Code: 8333, G-1-PU (Galactose-1-Phosphate Uridyltransferase), Galactosemia Enzyme (verify which test), Galactosemia, Galactose-1-Phosphate Uridyltransferase (GALT)
Useful For
​Diagnosis of galactose-1-phosphate uridyltransferase deficiency, the most common cause of galactosemia
 
Confirmation of abnormal state newborn screening results
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
​Whole blood EDTA Lavender Top Tube (LTT)​ ​ 5 mL​ 2 mL​ ​
Collection Processing Instructions
Additional Information: Patient's age is required.
Forms:  Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing is available in Special Instructions.​
Specimen Stability Information
Specimen Type Temperature Time
Whole blood​ Refrigerated (preferred)​ 28 days​
​ Ambient ​ 14 days​
Rejection Criteria
Gross hemolysis
​Gross lipemia
​Gross icterus
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​
 Monday, Tuesday, Thursday, Friday​
4 days (not reported on Saturday or Sunday)​
Ultraviolet, Kinetic​
Reference Lab
Mayo Clinic Laboratories
Test Information
​This assay is a quantitative measurement of the enzyme GPUT and provides an approximation of the patient's genotype. A deficiency of this enzyme is the most common cause of galactosemia. A galactokinase deficiency is the second most common cause of galactosemia. Those patients with GPUT values of 10.0 U/g hemoglobin or less should be definitively characterized by phenotyping (Test #80341 Galactose-1-Phosphate Uridyltransferase (GPUT) Biochemical Phenotyping, Erythrocytes). This test must be done prior to ordering #80341. This assay is not useful for diet monitoring of galactosemics.
Reference Range Information
> or =18.5 U/g of hemoglobin
Interpretation
​An interpretive report will be provided.
 
If elevated galactose levels remain unexplainable by either a defect in galactose-1-phosphate uridyltransferase or galactokinase, a specimen can be sent, upon request, to an external laboratory to rule out a defect in galactose-4-epimerase.
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​82775 ​ ​ ​ ​
Synonyms/Keywords
​Ref Lab Code: 8333, G-1-PU (Galactose-1-Phosphate Uridyltransferase), Galactosemia Enzyme (verify which test), Galactosemia, Galactose-1-Phosphate Uridyltransferase (GALT)
Ordering Applications
Ordering Application Description
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)		 Pediatric Minimum Volume
(no repeat)
​Whole blood EDTA Lavender Top Tube (LTT)​ ​ 5 mL​ 2 mL​ ​
Collection Processing
Additional Information: Patient's age is required.
Forms:  Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing is available in Special Instructions.​
Specimen Stability Information
Specimen Type Temperature Time
Whole blood​ Refrigerated (preferred)​ 28 days​
​ Ambient ​ 14 days​
Rejection Criteria
Gross hemolysis
​Gross lipemia
​Gross icterus
Useful For
​Diagnosis of galactose-1-phosphate uridyltransferase deficiency, the most common cause of galactosemia
 
Confirmation of abnormal state newborn screening results
Reference Range Information
> or =18.5 U/g of hemoglobin
Interpretation
​An interpretive report will be provided.
 
If elevated galactose levels remain unexplainable by either a defect in galactose-1-phosphate uridyltransferase or galactokinase, a specimen can be sent, upon request, to an external laboratory to rule out a defect in galactose-4-epimerase.
For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
Mayo Medical Laboratories​
 Monday, Tuesday, Thursday, Friday​
4 days (not reported on Saturday or Sunday)​
Ultraviolet, Kinetic​
Reference Lab
Mayo Clinic Laboratories
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)		 Quantity Description Comments
​82775 ​ ​ ​ ​
For most current information refer to the Marshfield Laboratory online reference manual.