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HelpTest Code GCT Galactosemia Reflex, Blood
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| GALZ | Galactosemia, Full Gene Analysis | Yes | No |
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Whole Blood EDTAOrdering Guidance
This test is appropriate for the diagnosis of, and routine carrier screening for, galactose-1-phosphate uridyltransferase deficiency.
This assay is not appropriate for monitoring dietary compliance. For dietary monitoring, order GAL1P / Galactose-1-Phosphate, Erythrocytes.
Necessary Information
Patient's age is required.
Specimen Required
Multiple whole blood tests for galactosemia can be performed on one specimen. Prioritize order of testing when submitting specimens. For a list of tests that can be ordered together, see Galactosemia-Related Test List.
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium heparin) or yellow top (ACD)
Specimen Volume: 5 mL
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimen in original tube. Do not aliquot.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood EDTA | Refrigerated (preferred) | 28 days | |
| Ambient | 14 days |
Reference Values
≥24.5 nmol/h/mg of hemoglobin
Day(s) Performed
Monday, Wednesday, Friday
CPT Code Information
82775
81406 (if appropriate)
Genetics Test Information
Preferred test to evaluate for possible diagnosis of galactosemia, routine carrier screening, and follow-up of abnormal newborn screening results. Comprehensive reflex test begins with quantitative galactose-1-phosphate uridyltransferase (GALT) enzyme analysis. If quantitative GALT enzyme value is less than 24.5 nmol/h/mg of hemoglobin, full gene sequencing of the GALT gene is performed.
Report Available
4 to 7 daysSpecimen Retention Time
2 monthsReject Due To
| Gross hemolysis | Reject |