An Unusual Course of a 2,8-Dihydroxyadeninuria Crystalline Nephropathy Secondary to Adenine Phosphoribosyltransferase Deficiency

Adenine phosphoribosyltransferase (APRT) deficiency is a rare disorder caused by an autosomal recessive genetic disease leading to the deposition of 2,8-dihydroxyadenine (2,8-DHA) in the kidney. The disease remains under-recognized, oftentimes diagnosed in late stages of renal insufficiency or a failed kidney allograft with biopsy-proven disease recurrence. Here, we present the case of a 59-year-old middle eastern male patient diagnosed with 2,8-DHA nephropathy after a very unusual presentation, and we show how the initiation of an appropriate therapy slowed down his evolution toward kidney replacement therapies. His disease was found to be secondary to a specific APRT gene variant c.188G>A p (Gly63Asp) also described in 4 other patients, all from middle eastern origins.

Automated summary

APRT deficiency is a rare disorder caused by an autosomal recessive genetic disease leading to the deposition of 2,8-DHA in the kidney, often diagnosed in late stages of renal insufficiency. This case report presents a Middle Eastern male patient diagnosed with 2,8-DHA nephropathy secondary to a specific APRT gene variant, shared with 4 other patients from the same region. Treatment initiation effectively slowed down disease progression towards kidney replacement therapies.