Phenotypic Variability of Kidney Involvement in Fabry Disease-Lessons from a Family Study

Fabry disease is an X-linked lysosomal storage disease that leads to the intracellular accumulation of glycosphingolipids in many tissues and fluids, including the kidneys. We report a single family with Fabry disease that includes seven patients carrying the pathogenic variant c.797A>C in the GLA gene, with remarkable variability in kidney involvement, assessed based on clinical, biological, and histological data. The patients were monitored for 2-9 years, and all received enzyme replacement therapy. Kidney involvement was variable and included severely decreased GFR with significant proteinuria, mildly to moderately decreased GFR with proteinuria, mildly decreased GFR with microalbuminuria or normoalbuminuria, hyperfiltration with normoalbuminuria, and preserved kidney function. All patients who underwent kidney biopsy presented with Fabry-specific lesions and, in some cases, chronic histological damage. This study provides valuable insights into kidney involvement evaluated through kidney biopsy, personalized management strategies for family members according to their phenotype, and long-term follow-up of kidney function. We underscore the importance of molecular screening of the GLA gene in all family members for early identification of the disease and early initiation of specific treatments that can prevent or delay the progression of this disease.