Galactose-1-Phosphate, Uridyl Trans.




Test Mnemonic

G1PHOS

CPT Codes

  • 82775 - QTY (1)

LOINC ®

10970-2

Aliases

  • Galactose-1-Phosphate Uridyltransferase (GALT Enzyme), RBC
  • Phosphogalactose Transferase

Performing Laboratory

ARUP


Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
7 mLWhole bloodSodium heparin (Green)Place specimen on ice after draw.RefrigeratedDo NOT freeze.

Alternate Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
7 mLWhole bloodLithium heparin (Green)Place specimen on ice after draw.RefrigeratedDo NOT freeze.
7 mLWhole bloodEDTA (Lavender)Place specimen on ice after draw.RefrigeratedDo NOT freeze.

Minimum Specimen Requirements

Volume Type Container Collect Temperature Transport Temperature Special Instructions
3 mL     

Stability

Environmental Condition Description
AmbientUnacceptable
Refrigerated5 days
FrozenUnacceptable

Days Performed

Mon, Wed, Fri

Turnaround Time

3 - 6 days

Methodology

Name Description
Enzymatic 
Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) 

Reference Range

Galactose-1-Phosphate, Uridyl Trans.
Sex Age From Age To Type Range Range Unit
       Normal> or = 19.4U/g Hb

Special Info

Do NOT freeze. Hemolyzed specimens are unacceptable. This test is New York DOH approved.

Clinical Info

Enzyme activity may not differentiate variant form of galactosemia or carriers. To monitor therapy in patients with galactosemia, order Galactose-1-Phosphate in red blood cells. One U/g Hb is equivalent to one umol/hour/gram of hb (umol/hr/g hb). Genotype/Galactose-1-Phosphate Uridyltransferase activity (┬Ámol h-1 gHb-1): Classic galactosemia (G/G), < or = 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), > or = 19.4