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).
||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|
Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.
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