Runolfsdottir HL, et al. - Researchers focused on the course of adenine phosphoribosyltransferase (APRT) deficiency (a hereditary purine metabolism disorder that causes kidney stones and chronic kidney disease [CKD])in patients who presented in childhood. They studied 21 (35%) patients in the APRT Deficiency Registry of the Rare Kidney Stone Consortium, 14 were placed on allopurinol, 100 (25–200) mg/day, at the age of 2.6 (0.6–16.5) years. Kidney stone events and acute kidney injury (AKI) prior to allopurinol treatment were reported in 6 and 3 of these patients, respectively. The occurrence of stones and AKI was reported in 2 and 3 patients, respectively, during 18.9 (1.7–31.5) years of pharmacotherapy. They reported 28 stone episodes and AKI in 5 and 2 of the 6 adult patients, respectively, who started allopurinol treatment, 200 (100–300) mg/day, at age 29.8 (20.5–42.4) years. In those who initiated treatment as children and adults, the estimated glomerular filtration rate (eGFR) at latest follow-up was 114 (70–163) and 62 (10–103) mL/min/1.73 m², respectively. When pharmacotherapy was started, all three patients with CKD stages 3–5 at the last follow-up were adults. Overall, attenuated renal complications and preserved kidney function can be achieved with timely diagnosis and treatment of APRT deficiency.