Galactose-1-Phosphate Uridyltransferase, Blood

Alphabetical Test listing

Galactose-1-Phosphate Uridyltransferase, Blood-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

GALT
G-1-PU (Galactose-1-Phosphate Uridyltransferase)
Galactosemia
Galactose-1-Phosphate Uridyltransferase (GALT)
Galactosemia Enzyme
Classical Galactosemia

Useful for:

Diagnosis of galactose-1-phosphate uridyltransferase deficiency, the most common cause of galactosemia

Confirmation of abnormal state newborn screening results

Limitations:

This assay is not appropriate for monitoring dietary compliance. If dietary monitoring is needed, order GAL1P / Galactose-1-Phosphate, Erythrocytes.

This test is for galactose-1-phosphate uridyltransferase (GALT) enzyme testing only. The preferred test to evaluate for possible diagnosis of galactosemia, routine carrier screening, and follow-up of abnormal newborn screening results is GCT / Galactosemia Reflex, Blood.

This assay will not detect galactokinase (GALK) deficiency or uridine diphosphate-galactose 4' epimerase (GALE) deficiency.

Patient preparation information:

The results of testing performed in erythrocytes, including analysis of enzymes, biochemical phenotyping, or galactose-1-phosphate are invalid following a transfusion. Patients should wait 3 to 4 months post transfusion before collecting whole blood for galactose-1-phosphate uridyltransferase testing.

Specimen type:

EDTA whole blood

Collection container:

Lavender (EDTA), 4mL

Volume:

5 mL

Minimum volume:

2 mL

Collection instructions:

Immediately following collection, mix sample thoroughly by gently inverting 8 - 10, times to prevent clotting

Alternate specimen type:

Sodium heparin (Na hep) whole blood
ACD whole blood

Alternate collection container:

Dk green Sodium heparin (Na hep) vial/tube (no gel) - 4 mL

Yellow ACD-solution B (ACD-B) vial/tube

Yellow ACD-solution A (ACD-A) vial/tube

Alternate transport container:

Submit entire specimen

Required forms/information:

Patient's age is required
Informed Consent for Genetic Testing
Biochemical Genetics Patient Information (recommended)

Transport and stability:

Refrigerated (preferred) - 28 days

Ambient - 14 days

Specimen retention time:

Processed RBC: 2 months

Reason for rejection:

Gross hemolysis

Performing lab:

Mayo Clinic Laboratories (GALT): R-NX

Days set up:

Mo, We, Fr

TAT:

3 - 6 days

Method:

Enzyme Reaction followed by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reference ranges:

≥ 24.5 nmol/h/mg of hemoglobin

Clinical information:

Galactose-1-phosphate uridyltransferase (GALT) deficiency is the most common cause of galactosemia and requires lifelong restriction of dietary galactose.

Classic galactosemia can be diagnosed by analysis of GALT enzyme.

This test provides enzymatic testing for the diagnosis of GALT deficiency.

For more information see Galactosemia Testing Algorithm.

CPT codes:

82775

Date created:

02/13/2023

Revised date:

02/14/2023

Review date:

02/13/2023