[A method of diagnosing congenital adenylosuccinase enzymopathy]

The authors present a simple and convenient method for the diagnosis of a recently described condition, congenital adenyl succinase enzymopathy, that is characterized, among other signs, by the appearance in patients' urine of succinylaminoimidazole carboxamide riboside (SAICRs) and succine adenosine (SA), dephosphorylated (nucleoside) forms of two adenylsuccinase substrates. Both the nucleosides may be sorbed by ion exchanger when the urine is let pass through H+ cationite and then eluated by solved ammonia (earlier this was known only in respect of SAICRs). The new feature of the procedure is detection of the afore-said nucleosides in ammonia eluate from its UV spectrum. The value of the ratio between ammonia eluate absorption in 270 and 250 nm (A270/A250) was found a reliable criterion of both SAICRs and SA absence in the urine and therefore of a normal adenyl succinase level (A270/A250 ratio is 0.25-0.45 in this case) and of their presence in the urine and therefore of their presence of adenyl succinase enzymopathy (A270/A250 ratio, above 0.70, typically 0.90-1.0).