Types of Stones
is an extremely uncommon metabolic condition in which a deficiency
of the enzyme phosphoribosyl transferase (APRT) results in the conversion
of adenine 2,8 -dyhydroxyadenine, a poorly soluble substance that
readily crystallizes in urine. This results in DHA renal calculi,
which have been identified primarily in children who would appear
to have no other manifestations of their disease. Similar to uric
acid stones they are radiolucent. However, unlike uric acid calculi,
they are much more soluble in acidic pH than in an alkaline pH.
Manyak MJ, Frensilli FJ, Miller HC: 2,8-Dyhydroxyadenine urolithiasis:
Report of an adult case in the United States. J Urol 137:312, 1987.