We report two cases of 2,8-DHA crystalline nephropathy caused by APRT deficiency in a 19-year-old male who initially presented with acute kidney injury and obstruction, and a 53-year-old male with unexplained progressive CKD, and the diagnosis was only made post kidney transplant following delayed graft function. This evidence concerns the gene APRT and hyperinsulinemic hypoglycemia, familial, 4.