Successful Renal Transplantation in a 15-Year-Old Girl with Nephropathic Cystinosis: A Case Report

Cystinosis is an autosomal recessive lysosomal storage disorder( bi‐allelic mutations in the CTNS gene) characterized by the defective transport of the amino acid cystine out of the lysosome due to a deficiency of cystinosin, the lysosomal cystine transporter. Patients have lysosomal cystine ac‐ cumulation in various tissues, leading to cellular stress and damage, particularly in the kidney, cornea, and other extrarenal tissues. Cysteamine, a cystine‐depleting agent, improves survival and delays the progression of disease, but it does not prevent the development of either renal failure or extrarenal complications. Furthermore, the drug has severe adverse effects that significantly reduce patient compliance. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently established as a therapeutic option for many inborn errors of metabolism, where the main pathologic driving factor is an enzyme deficiency.Nephropathic cystinosis is a rare autosomal recessive lysosomal storage disorder that leads to progressive renal failure, often necessitating renal transplantation. We present the case of a 15-year-old girl with end-stage renal disease (ESRD) secondary to nephropathic cystinosis, successfully managed with a live donor renal transplantation.