Is adenine phophorybosiltransferase deficiency a still underdiagnosed cause of urolithiasis and chronic renal failure? A report of two cases in a family with an uncommon novel mutation.

We describe two patients that had a history of recurrent renal stones and chronic renal insufficiency. The first case was a 51-year-old man with an adenine phophoribosyltransferase (APRT) deficiency who was diagnosed only after he had been referred for severe renal failure requiring hemodialysis. This led to a screening of the entire family, which identified six carriers and an additional affected relative (a 41-year-old man and the second case reported herein). Genetic analysis of the APRT gene revealed an atypical mutation previously described only once in a compound heterozygote.