Galactokinase, Blood
Use
This test is useful for the diagnosis of galactokinase deficiency, a very rare autosomal recessive disorder affecting the first step of galactose metabolism. It helps evaluate children with unexplained bilateral congenital or juvenile onset cataracts, which is a major clinical manifestation of this deficiency. The disorder has a higher frequency in the Romani population, and a prevalence estimated to be between 1 in 50,000 to 1 in 100,000 live births. Early detection and treatment with a galactose-restricted diet may prevent or reverse cataract formation.
Special Instructions
Not provided.
Limitations
This assay cannot detect deficiencies in galactose-1-phosphate uridyltransferase (GALT), uridine diphosphate-galactose 4' epimerase (GALE), or galactose mutarotase (GALM). Improper specimen collection and handling, post-transfusion samples, or inappropriate test selection can lead to diagnostic confusion. The test results are invalid after a transfusion due to potential interference with readings.
Methodology
Mass Spectrometry (LC-MS/MS)
Biomarkers
Galactokinase
Analyte
LOINC Codes
- 81143-0 - Galactokinase RBC-cCnt
- 81143-0 - Galactokinase RBC-cCnt
- 59462-2 - Clinical biochemist review
- 18771-6 - Provider signing name
Result Turnaround Time
5-11 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
4 mL
Minimum Volume
2 mL
Container
Preferred: Lavender top (EDTA); Acceptable: Green top (sodium or lithium heparin) or yellow top (ACD)
Collection Instructions
Multiple whole blood tests for galactosemia can be performed on 1 specimen. Prioritize order of testing when submitting specimens.
Causes for Rejection
Gross hemolysis
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 10 days |
