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Test Code AGA Alpha-Galactosidase, Leukocytes

Performing Laboratory

Mayo Medical Laboratories in Rochester

Reporting Name

Alpha-Galactosidase, Leukocytes

Method Name


Useful For

Diagnosis of Fabry disease in males


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

Specimen Required

Specimen must arrive 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.



Preferred: Yellow top (ACD solution B)

Acceptable: Yellow top (ACD solution A)

Specimen Volume: 7 mL

Collection Instructions: Do not transfer blood to other containers.


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 (Supply T576) is available in Special Instructions.

2. If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

Biochemical Genetics Request Form (Supply T439)

Neurology Test Request Form (T732) (

3. Biochemical Genetics Patient Information (Supply T602) in Special Instructions.

Specimen Type

Whole Blood ACD

Specimen Minimum Volume

6 mL

Reject Due To


Mild OK; Gross reject







Specimen Stability Information

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

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 (FABMS / Fabry Disease, Full Gene Analysis) is recommended as the appropriate diagnostic test for females.

Analytic Time

8 days

Day(s) and Time(s) Performed

Specimens are processed Monday through Sunday.

Assay is performed on Tuesday.

Specimen Retention Time

WBC homogenate stored 1 month

CPT Code Information


LOINC Code Information

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

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.

Testing Algorithm

The following algorithms are available in Special Instructions:

-Fabry Disease: Newborn Screen-Positive Follow-up

-Fabry Disease Testing Algorithm