Living Kidney Transplantation in a Patient With End‐Stage Kidney Disease Due to Rare Juvenile Nail‐Patella‐Like Renal Disease Without LMX1B Mutation

Nail‐patella syndrome (NPS) is a rare disease characterized by fingernail dysplasia, patellar dysplasia, elbow deformities, and iliac horns, with a prevalence of 1 in 50,000 children. Most cases are caused by LMX1B mutations. Approximately 10%–40% of patients with NPS develop renal dysfunction in early childhood, whereas approximately 30% progress to end‐stage renal disease (ESRD). In addition, a few reports describe NPS without LMX1B mutations, but the mechanism affecting renal function is still unclear. In particular, nail‐patella‐like renal disease (NPLRD) presents solely with nephropathy without the physical changes that are characteristic of NPS. Herein, we report a case of clinicopathological NPLRD with characteristic NPS findings on electron microscopy but without physical features or LMX1B mutation, as confirmed by whole exome sequencing. The patient subsequently progressed to ESRD and underwent living‐related kidney transplantation. Seven years posttransplantation, no renal function‐related events occurred, and the patient returned to social activities without complications.