Challenges in Fabry disease: the combination of two individually amenable GLA variants may be nonamenable to migalastat.

Fabry disease is a rare lysosomal storage disorder caused by mutations in the GLA gene, resulting in reduced or absent α-Gal A activity. Migalastat is an oral chaperone therapy for Fabry patients with amenable GLA variants. We previously reported a case of a 60-year-old male patient with a classic phenotype of Fabry disease, presenting with two GLA variants: p.R356Q and p.G360R. Herein, we report that, although these two missense variants are individually classified as amenable to migalastat in the validated in vitro human embryonic kidney-293 cell-based assay, their combination precludes the patient to be treated with this oral chaperone. This case illustrates how therapeutic decisions may be challenging and how a good genotypic characterization of Fabry patients is critical for the selection of the correct therapeutic strategy.