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Test Code LAB1231782 Galactose-1-Phosphate, Erythrocytes

Important Note

Mayo code is GAL1P

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Reporting Name

Galactose-1-Phosphate, RBC

Specimen Type

Whole Blood EDTA


Ordering 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


Reject Due To

Gross hemolysis Reject

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated 72 hours

Specimen Minimum Volume

2 mL

Day(s) Performed

Thursday

Specimen Retention Time

1 month

Report Available

4 to 10 days

Reference Values

Reference interval (normal range): ≤0.9 mg/dL

Therapeutic range: ≤4.9 mg/dL

Useful For

Monitoring dietary therapy of patients with galactosemia due to deficiency of galactose-1-phosphate uridyltransferase or uridine diphosphate galactose-4-epimerase

Testing Algorithm

For more information see Galactosemia Testing Algorithm.

CPT Code Information

84378

LOINC Code Information

Test ID Test Order Name Order LOINC Value
GAL1P Galactose-1-Phosphate, RBC 2312-7

 

Result ID Test Result Name Result LOINC Value
24101 Galactose-1-Phosphate, RBC 2312-7

Disease States

  • Galactosemia

Genetics Test Information

Galactose-1-phosphate uridyltransferase (GALT) deficiency is the most common cause of galactosemia and requires lifelong restriction of dietary galactose.

 

Galactose-1-phosphate is elevated in patients with galactosemia due to GALT deficiency or uridine diphosphate galactose-4-epimerase deficiency, therefore is a suitable analyte for monitoring dietary compliance.

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.