Test Code GAL1P Galactose-1-Phosphate, Erythrocytes
Testing Algorithm
For more information see Galactosemia Testing Algorithm.
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Whole Blood EDTAOrdering Guidance
This test is used to monitor dietary therapy of patients with galactosemia due to deficiency of galactose-1-phosphate uridyltransferase or uridine diphosphate galactose-4-epimerase.
This test is not appropriate for the diagnosis of galactosemia. The preferred test to evaluate for possible diagnosis of galactosemia, routine carrier screening, and follow-up of abnormal newborn screening results is GCT / Galactosemia Reflex, Blood.
This test is not appropriate for the diagnosis of epimerase deficiency, the preferred test to evaluate this deficiency is GALE / Uridine Diphosphate-Galactose 4' Epimerase, Blood.
If GAL1P / Galactose-1-Phosphate, Erythrocytes testing is needed, the test can be added to existing specimens if they were received in the testing laboratory within 72 hours of collection.
Necessary Information
Biochemical Genetics Patient Information (T602) is recommended, but not required, to be filled out and sent with the specimen to aid in the interpretation of test results.
Specimen Required
Multiple whole blood tests for galactosemia can be performed on 1 specimen. Prioritize order of testing when submitting specimens. For a list of tests that can be ordered together, see Galactosemia-Related Test List.
Patient Preparation: Specimens collected following a meal can exhibit postprandial elevations. For infants, collect a specimen immediately prior to feeding to avoid this.
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium heparin)
Specimen Volume: 3 mL
Specimen Minimum Volume
2 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole Blood EDTA | Refrigerated | 72 hours |
Special Instructions
Reference Values
Reference interval (normal range): ≤0.9 mg/dL
Therapeutic range: ≤4.9 mg/dL
Day(s) Performed
Thursday
CPT Code Information
84378
Report Available
4 to 10 daysReject Due To
Gross hemolysis | Reject |
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
1. Biochemical Genetics Patient Information (T602) is recommended.
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.