However, making the diagnosis of APRT deficiency is also extremely variable, just like the clinical course of the disease, and this is attributable to the radiolucent composition of DHA crystals, which often leads to a misdiagnosis of uric acid stones and the fact that these crystals also mimic oxalate crystals [1]. This evidence concerns the gene APRT and hyperinsulinemic hypoglycemia, familial, 4.