Monarch Disease Ontology entry MONDO_0013869 (adenine phosphoribosyltransferase deficiency) can be described as follows. Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive (AR) disorder characterized by the formation and hyperexcretion of 2,8-dihydroxyadenine (2,8-DHA) in urine, causing urolithiasis and crystalline nephropathy. Also known as: 2,8-dihydroxyadenine urolithiasis, 2,8-dihydroxyadeninuria disease, APRT deficiency.