Evaluation of Cystinosis Patients and Factors Associated with Chronic Kidney Disease

Introduction: Cystinosis is a rare genetic, lysosomal storage disorder, leading to kidney involvement and other organs. The most critical factor determining the prognosis is its impact on the kidneys especially nephropatic cystinosis. This study aimed to evaluate cystinosis patients and identify factors associated with chronic kidney disease (CKD). Methods: The medical records of 18 nephropatic cystinosis patients were retrospectively reviewed. Demographic and clinical features, prognosis were evaluated. Patients were classified according to their estimated glomerular filtration rate (eGFR) at last visit as eGFR60 ml/min/1.73 m2, and were compared for CKD related factors. Results: The mean age at diagnosis was 46.61±50.42 months. The most common allel was c. 451A>G. Polyuria, polydipsia, vomiting, growth retardation, and renal osteodystrophy were typical presenting symptoms. At diagnosis, the mean eGFR was 72.94±21.69 ml/min/1.73 m². After an average follow-up of 68.28±60.18 months, the mean eGFR was 63.97±23.59 ml/min/1.73 m², and CKD was observed in 44.4% of patients, and 5 (27.8%) underwent kidney replacement theraphy (KRT). In patients with GFR