An alternative method for screening fabry disease in women: partial results of a brazilian study.

Abstract

Background and Aims: Fabry disease (FD) is a rare X-linked lysosomal storage disease that can affect multiple organs, including the kidneys. The main objective of this study was to evaluate the effectiveness of a combination of α-GAL enzyme activity and plasma levels of lyso-GL3 for screening FD in women with chronic kidney disease (CKD). Method: Women with CKD, stages 3 to 5, in regular nephrological follow-up were selected from renal centers in all regions of Brazil. Exclusion criteria: under 18 years old and known diagnosis of CKD. Patients underwent biochemical analysis of α-GAL enzyme activity and plasma levels of lyso-GL3. GLA gene sequencing was performed if α-GAL enzyme activity was below and/or lyso-GL3 levels were above the reference range. Sensitivity and specificity analyzes were performed to evaluate the performance of the combined biochemical approach for the diagnosis of FD. Results: From October 2020 to December 2022 1,647 collections were carried out. Low α-GAL activity was found in 44 (2.6%) of the cases and increased lyso-GL3 was found in 101 (6.1%) of the cases. The mean age was 53 [42 – 64] years. All cases of low α-GAL and/or increased lyso-GL3 were submitted to genetic analysis, and 6 positive cases were found. As for genetic variants, four patients have R118C, one A143T and other with T430G, all considered variants of uncertain significance (VUS). The sensitivity and specificity of α-GAL reduction for the detection of FD was 83.3% and 97.6%, respectively. As for the increase in lyso-GL3, the values were 16.6% and 93.9%, respectively. There were no cases that presented a concomitant increase in lyso-GL3 and a reduction in enzymatic activity. Conclusion: Preliminary results suggest that the combination of α-GAL enzymatic activity with lyso-GL3 measurement may be a good alternative for screening FD in women with CKD. A thorough medical evaluation is required to determine the pathogenicity of variants in these patients.