Your healthcare provider may order tests to diagnose Fabry disease, including: Enzyme assay: This test measures alpha-GAL enzymes in blood. Measurements of 1% or lower indicate disease. This test is most reliable for males and should not be used in females. Genetic: Because females with Fabry disease can have normal levels of alpha-GAL enzymes, providers use genetic testing (DNA sequencing) to identify the GLA gene mutation. Newborn screenings: Some states test newborns for Fabry disease and other lysosomal storage disorders. The enzyme test is included as part of routine newborn screenings.