Ordering Recommendation

Use to monitor treatment, response, and compliance with dietary restriction for patients with an established diagnosis of galactosemia. To diagnose or rule out galactosemia, refer to Galactosemia (GALT) Enzyme Activity and 9 Mutations (0051175).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Lavender (EDTA) or green (sodium or lithium heparin).

Specimen Preparation

DO NOT FREEZE. Place tube on wet ice immediately after collection. Transport 5 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature


Unacceptable Conditions

Frozen or room temperature specimens.


Ambient: Unacceptable; Refrigerated: 72 hours; Frozen: Unacceptable


Gas Chromatography-Mass Spectrometry (GC-MS)


Tue, Thu


2-9 days

Reference Interval

Test Number
Reference Interval
  Galactose-1-phosphate (mg/dL) 0.0-1.0 mg/dL
  Galactose-1-phosphate (ug/g Hb) 0-53 ug/g Hb
  Galactose-1-phosphate (umol/g Hb) 0.00-0.20 umol/g Hb

Interpretive Data

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.

Compliance Category

Laboratory Developed Test (LDT)


Alternate acceptable specimen is frozen, washed red blood cells.
1. Centrifuge whole blood immediately for 10 minutes at 800 g RCF.
2. Discard the plasma and buffy coat layers.
3. Add cold 0.9 percent saline solution to the red cells (about 2 times the volume of cells) and mix gently by inverting the tube.
4. Centrifuge for 10 minutes at 800 g RCF.
5. Aspirate and discard the supernatant.
6. Repeat the wash (steps 3 through 5) 2 more times.
7. After the 3rd wash and centrifugation, remove the supernatant and a thin layer of the top cells. 
8. Transfer washed cells to an ARUP standard transport tube and freeze. Ship on dry ice and include an ORDER COMMENT stating the specimen is washed, packed red blood cells.
Washed red cells must be frozen.  Ambient and refrigerated washed cells are unacceptable

Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
0081298 Galactose-1-phosphate (mg/dL) 2312-7
0081299 Galactose-1-phosphate (ug/g Hb) 33360-9
0081300 Galactose-1-phosphate (umol/g Hb) 38485-9
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Gal1P
  • Galactose 1
  • Galactose 1 Phosphate
  • Galactosemia Analyte
  • Galactosemia Metabolite(s)
  • GALT Analyte
Galactose-1-Phosphate in Red Blood Cells