Diagnosis

Establish or confirm diagnosis

Diagnosis of Fabry disease in male patients. This test is not useful for patients undergoing a work up for a meat or meat-derived product allergy.

Alpha-galactosidase is a lysosomal enzyme active at an acidic pH. The enzyme hydrolyzes artificial substrates such as 4-methylumbelliferyl and alpha-D galactopyranoside. The 4-methylumbelliferone liberated is measured by fluorometry.(Desnick RJ, Allen KY, Desnick SJ, et al: Fabry's disease: enzymatic diagnosis of hemizygotes and heterozygotes. Alpha-galactosidase activities in plasma, serum, urine, and … Alpha-galactosidase is a lysosomal enzyme active at an acidic pH. The enzyme hydrolyzes artificial substrates such as 4-methylumbelliferyl and alpha-D galactopyranoside. The 4-methylumbelliferone liberated is measured by fluorometry.(Desnick RJ, Allen KY, Desnick SJ, et al: Fabry's disease: enzymatic diagnosis of hemizygotes and heterozygotes. Alpha-galactosidase activities in plasma, serum, urine, and leukocytes. J Lab Clin Med. 1973 Feb;81[2]:157-171; Cowan T, Pasquali M: Laboratory investigations of inborn errors of metabolism. In: Sarafoglou K, Hoffman GF, Roth KS, eds. Pediatric Endocrinology and Inborn Errors of Metabolism. 2nd ed. McGraw-Hill; 2017:1139-1158) View more

Tests performed
Entire test performed in-house

Accuracy was assessed by method comparison of positive and negative samples and was acceptable. Intra assay precision was performed at 3 levels: CV results ranged from 4.4%-5.5% (N=20 each). Inter assay precision was performed at 3 levels: CV results ranged from 11.2%-11.5% (N=20 each). The analytical measurement range is 0.0 … Accuracy was assessed by method comparison of positive and negative samples and was acceptable. Intra assay precision was performed at 3 levels: CV results ranged from 4.4%-5.5% (N=20 each). Inter assay precision was performed at 3 levels: CV results ranged from 11.2%-11.5% (N=20 each). The analytical measurement range is 0.0 – 1.028 nmol/min/mL View more

Individuals with pseudodeficiency allelic variants can show reduced alpha-galactosidase A enzyme activity with this assay.

Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Intra-Laboratory

Description of PT method: Help
Intra-laboratory alternative assessment of performance through quality control or patient blind testing

Description of internal test validation method: Help
This test was laboratory developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements.