Diagnosis of Fabry disease

alpha-Gal A: alpha-galactosidase A; GLA: galactosidase alpha; Gb3: globotriaosylceramide.
* Refer to UpToDate topics on the clinical features and diagnosis of Fabry disease.
¶ Alpha-Gal A activity is expressed as a percentage of the mean normal level.
Δ Although genetic testing is not required to establish the diagnosis of Fabry disease in these patients, it should be performed, unless a familial mutation has already been identified. Genetic testing in this setting facilitates diagnosis and genetic counseling in the patient's family and establishes the patient's amenability to treatment with chaperone therapy (ie, migalastat).
◊ In males with decreased but detectable alpha-Gal A leukocyte activity, a diagnosis of Fabry disease is likely established since some hemizygous males and males with atypical variants may have alpha-Gal A leukocyte activity within this range.
§ Genetic testing can be deferred if the patient has a known family history of Fabry disease and a familial mutation has already been identified.
¥ In females with the cardiac variant of Fabry disease, there are insufficient data that a kidney biopsy without evidence of intracellular Gb3 inclusions completely excludes the diagnosis of Fabry disease.