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HelpTest Code LAB995 Galactose 1 Phosphate, Metabolite Quantification
Clinical System Name
Galactose 1 Phosphate, Metabolite Quantification
Synonyms
G1P; Gal-1-P; GAL1P;
Description
Used to monitor treatment of known Galactosemia patients.
Sample Requirements
Specimen: Whole Blood
Container(s): Dark Green/Sodium Heparin Tube, Yellow/ACD A or B, Lavender/EDTA
Preferred Vol: 2.0 mL
Minimum Vol: 1.0 mL
Note: Do NOT use gel separator tubes.
Processing Instructions
Reject due to:
Spin: N
Aliquot:N
Temp: RT
Special instructions: Notify Biochemical Genetics (987-2216) immediately so that cells can be washed before storing at -70 C. If not available, follow "Weekend Processing" instructions below. Blood collection on adults is permitted.
Weekend Processing: Call Chemistry West (987-2565). Procedure can be found in RBC enzyme section.
Off-site collection: Special processing required. Call biochemical genetics prior to collection with questions about processing. Samples received from outside labs should be frozen washed cells. Store cells at -70 C (although -20 C is acceptable for short term transport). Cells must not thaw during transport.
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| whole blood | Room temp |
≤1 h after collection |
| whole blood | Refrigerated | < 1 h after collection |
| washed, frozen red cells | > -20C | stable if cells remain frozen on transport |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | Weekly | 7 d |
Contact the Biochemical Genetics Lab for requests outside of stated availability (206)987-2216.
Performing Laboratory
Seattle Children's Laboratory
Department
Department: Biochemical Genetics
Phone Number: 206-987-2216
Methodology
Method: Fluorometric
Analytical Volume:
Limitations:
Reference Range
| Range | |
|
Preferred range for patients with galactosemia |
< 4 mg/dL |
| Normal range for patients without galactosemia | <1 mg/dL |
CPT Codes
84378
Requisition
Biochemical Genetics Requisition
On the requisition include clinical information needed for appropriate interpretation. (Age, gender, drug therapy and family history)
Clinical Utility
Galactosemia is an inherited disorder of galactose metabolism. Individuals with galactosemia are unable to break down galactose, a sugar found primarily in dairy products and some vegetables and legumes. Galactosemia is caused by a deficiency in the enzyme galactose-1-phosphate uridyltransferase, and individuals with galactosemia have mutations in the GALT gene. They also have elevated galactose-1-phosphate, a metabolite of galactose metabolism that is used for dietary monitoring in affected patients. Patients with defects in the GALE gene (UDP-galactose-4-epimerase deficiency) would also have elevated galactose-1-phosphate. patients with defects in the GALK gene (galactokinase deficiency) would have normal galactose 1-phosphate, but elevated galactose.