Initial test to diagnose or rule out galactosemia.
Enzymatic/Liquid Chromatography-Tandem Mass Spectrometry
Mon, Wed, Fri
Green (Sodium or Lithium Heparin), Lavender (K2EDTA), or Pink (K2EDTA). Collect on ice.
DO NOT FREEZE. Transport 7 mL whole blood. (Min: 3 mL)
Ambient: Unacceptable; Refrigerated: 5 days; Frozen: Unacceptable
Greater than or equal to 19.4 U/g Hb
One U/g Hb is equivalent to one umol/hour/gram of hemoglobin (umol/hr/g Hb).
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
||Galactose-1-Phosphate Uridyltransferase activity (umol/hr/g Hb)
|Classic galactosemia (G/G)||Less than or equal to 0.7|
|Duarte galactosemia (D/G)||3.1-7.8|
|Classic galactosemia carrier (G/N)||6.5-16.2|
|Duarte homozygous (D/D)||6.4-16.5|
|Duarte carrier (D/N)||12.0-24.0|
|Normal (N/N)||Greater than or equal to 19.4|
Laboratory Developed Test (LDT)
Values for enzyme activity only may not differentiate between variant form of galactosemia or carriers. For a more accurate evaluation of patients suspected to have galactosemia, the preferred test is Galactosemia (GALT) Enzyme Activity and 9 Mutations (ARUP test code 0051175). To monitor therapy in patients with galactosemia, order Galactose-1-Phosphate in Red Blood Cells (ARUP test code 0081296).
|Component Test Code*||Component Chart Name||LOINC|
- Classic Galactosemia
- Erythrocyte Galactose-1-Phosphate Uridyltransferase Phenotyping
- GALT ENZYME
- GALT Phenotype