Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive inherited disorder of purine metabolism that usually manifests as 2,8-dihydroxyadenine (DHA) nephropathy due to excessive DHA crystal deposition in the tubular lumen and interstitium of the kidney, leading to inflammation and severely impaired renal function22. The gene discussed is APRT; the disease is kidney disorder.