Preliminary Screening Results of Fabry Disease in Kidney Transplantation Patients: A Single-Center Study

Abstract

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by the deficiency of alfa-galactosidase A (AGALA) and leads to progressive impairment of renal function in almost all male patients and in a significant proportion of female patients. FD is underdiagnosed or even misdiagnosed in patients undergoing kidney transplantation. We initiated a selective screening study for FD among kidney transplant patients in our center. In this study, 1095 male and female patients were included. Dried blood samples on Guthrie papers were used to analyze galactosidase A enzyme for male patients. Genetic analyses were performed in all female and male patients with low enzyme activity. In total, 648 female and 447 male patients with functioning grafts were evaluated. Among 1095 patients, 5 male patients had AGALA activity below threshold and 3 female patients had galactosidase alpha gene DNA variations. One male patient had a disease-causing mutation. The other 4 patients had polymorphisms causing low enzyme activity. All the 3 female patients had mutations that were associated with FD according to Human Gene Mutation Database (ID: CM025441). In contrast, these mutations were reported as unknown clinical significance in Clinvar (rs149391489). The patients with clinical findings suggesting FD were planned to be analyzed for Lyso Gb3. In our selective screening study, 8 variations were found among 1095 kidney transplantation patients, which needs further investigation to determine causes of FD. Clinical findings, physical examination, and family history are also necessary to evaluate the genetic changes as a mutation in this selected population.