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Test Code AGA Alpha-Galactosidase, Leukocytes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Useful For

Diagnosis of Fabry disease in males


Verifying abnormal serum alpha-galactosidase results in males with a clinical presentation suggestive of Fabry disease

Testing Algorithm

The following algorithms are available in Special Instructions:

-Fabry Disease: Newborn Screen-Positive Follow-up

-Fabry Disease Testing Algorithm


For more information, see Newborn Screening Act Sheet Fabry Disease: Decreased Alpha-Galactosidase A in Special Instructions.

Method Name


Reporting Name

Alpha-Galactosidase, Leukocytes

Specimen Type

Whole Blood ACD

Advisory Information

Enzyme levels for carriers are usually within the normal range. Order FABRZ / Fabry Disease, Full Gene Analysis for carrier testing.

Shipping Instructions

For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerated within 72 hours of draw to be stabilized. Specimen received after 72 hours could have falsely normal results. Draw specimen Monday through Thursday only and not the day before a holiday. Specimen should be drawn and packaged as close to shipping time as possible.

Specimen Required


Preferred: Yellow top (ACD solution B)

Acceptable: Yellow top (ACD solution A)

Specimen Volume: 6 mL

Collection Instructions: Do not transfer blood to other containers.

Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole Blood ACD Refrigerated (preferred) 72 hours
  Ambient  72 hours

Reject Due To


Mild OK; Gross reject







Reference Values

≥23.1 nmol/hour/mg protein

An interpretative report will be provided.

Note: Results from this assay do not reflect carrier status because of individual variation of alpha-galactosidase enzyme levels.


Deficiency of alpha-galactosidase A (alpha-Gal A) is diagnostic for Fabry disease in males.


Urine sediment analysis (CTSA / Ceramide Trihexosides and Sulfatides, Urine) for the accumulating trihexoside substrate is also recommended.


Carrier females usually have alpha-galactosidase levels in the normal range; therefore, molecular sequence analysis of the GLA gene (FABRZ / Fabry Disease, Full Gene Analysis) is recommended as the appropriate diagnostic test for females.

Day(s) and Time(s) Performed


Analytic Time

8 days

Specimen Retention Time

WBC homogenate stored 1 month

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
AGA Alpha-Galactosidase, Leukocytes 24049-9


Result ID Test Result Name Result LOINC Value
32302 Reason for Referral 42349-1
32303 Method 49549-9
8785 Alpha-Galactosidase, Leukocytes 24049-9


1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. Biochemical Genetics Patient Information (T602) in Special Instructions