Test Catalog

Test ID: GAL1P    
Galactose-1-Phosphate, Erythrocytes

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Galactosemia Testing Algorithm in Special Instructions

Specimen Type Describes the specimen type validated for testing

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 (GALT) or uridine diphosphate galactose-4-epimerase (GALE).


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 / UDP-Galactose 4' Epimerase, Blood.

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 Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Multiple whole blood tests for galactosemia can be performed on 1 specimen. Prioritize order of testing when submitting specimens. See Galactosemia-Related Test List in Special Instructions for a list of tests that can be ordered together.


Patient Preparation: Specimens collected following a meal can exhibit postprandial elevations. For infants, collect a specimen immediately prior to feeding to avoid this.


Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium heparin)

Specimen Volume: 3 mL

Special Instructions Library of PDFs including pertinent information and forms related to the test


1. Biochemical Genetics Patient Information (T602) is recommended, see Special Instructions.

2. If not ordering electronically, complete, print, and send an Inborn Errors of Metabolism Test Request (T798) with the specimen.

Specimen Minimum Volume Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

2 mL

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen TypeTemperatureTimeSpecial Container
Whole Blood EDTARefrigerated72 hours