Impaired kinetic properties of hypoxanthine-guanine phosphoribosyl transferase as a cause of uric acid nephropathy in early infancy.
A 6-month-old infant presented with failure to thrive, hyperuricaemia and renal insufficiency. The hyperuricaemia was due to uric acid over-production. The level of hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity was found to be normal. However, a two-fold increase in the Km of the enzyme to hypoxanthine as well as in the Vmax values was observed. It seems therefore, that in cases of uric acid over-production, screening tests of HGPRT activity may be insufficient and additional kinetic properties of the enzyme should be tested.
Kerem
E
E
Department of Pediatrics, Bikur Cholim General Hospital, Jerusalem, Israel.
Branski
D
D
Gross-Kieselstein
E
E
Hurvitz
H
H
Abrahamov
A
A
Pollack
Y
Y
D058186:Acute Kidney Injury / Q000201:enzymology / Q000209:etiology*; D003241:Consanguinity; D005183:Failure to Thrive / Q000201:enzymology / Q000209:etiology; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000378:metabolism*; D007223:Infant; D007700:Kinetics; D008297:Male; D014527:Uric Acid / Q000378:metabolism*
D014527:Uric Acid; D007041:Hypoxanthine Phosphoribosyltransferase