Table 1 here
In males α-galactosidase A activity was 15.0±5.23 (range 3.2-36.6) pmol/punch/hr. Reduced α-galactosidase activity (<6.3pmol/punch/hr) was found in 7 male subjects from 505 tested. Low activity in DBS samples can be due to many factors including a low white blood count, or inadequate sample drying. These subjects were recalled for a second analysis: 2 subjects declined and 5 repeat tests were normal. In females α-galactosidase activity was 5.2±2.4 (range 0.7-28.8) µmol/l/hr and 1 subject from 579 tested had reduced α-galactosidase activity (<1.2 µmol/l/hr). No pathogenic mutations were found in patients with low α-galactosidase activity. A further 16 samples from females with normal range α-galactosidase activity had elevated Lyso-GL-3. One female subject (age 55, eGFR 40ml/min/1.73m2) had α-galactosidase activity 1.5 µmol/l/hr, but Lyso-GL-3 5.5 ng/ml and was identified as heterozygous for a FD mutation (c.898C>T; p.L300F; Leu300Phe). She knew that her mother had Fabry disease but had not been previously tested.