Acquired cystinuria in a kidney transplant recipient

Cystinuria is a rare autosomal recessive hereditary disorder characterized by increased urine cystine excretion and recurrent kidney stone formation. Acquired cystinuria after kidney transplantation is extremely rare, with, to our knowledge, a single case described in the literature, albeit without genetic explorations. We herein report a 59-year-old male kidney transplant recipient, without history of urolithiasis, who developed cystine stones in the allograft. Genetic studies revealed a homozygous pathogenic mutation in the SLC3A1 gene in the deceased donor. This case demonstrates the potential for transmission of cystinuria through the kidney allograft and underlines the value of genetic analysis in the donor.