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HPRT‐Deficiency associated with normal PRPP concentration and APRT activity
Author(s) -
Gordon R. B.,
Keough D. T.,
Emmerson B. T.
Publication year - 1987
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf01799493
Subject(s) - hypoxanthine guanine phosphoribosyltransferase , lesch–nyhan syndrome , hypoxanthine phosphoribosyltransferase , hypoxanthine , lymphoblast , adenine phosphoribosyltransferase , gout , purine , purine metabolism , nucleotide , chemistry , de novo synthesis , nucleotide salvage , biochemistry , medicine , endocrinology , biology , enzyme , cell culture , genetics , mutant , gene
Deficiencies of HPRT are usually associated with increased concentrations of PRPP and increased levels of APRT activity in erythrocytes. We report the case of a male with a partial deficiency of HPRT in whom these two parameters were normal. The clinical features of this patient were those associated with severe hyperuricaemia and gout. Studies of intact erythrocytes showed rates of incorporation of [ 14 C]hypoxanthine and of [ 14 C]adenine into purine nucleotides which were almost indistinguishable from normal. However, HPRT activity in erythrocyte lysates was only 9% of normal. In cell extracts of cultured lymphoblasts, the HPRT activity was 20% of control values and the APRT activity was normal. The PRPP concentration and the rate of de novo purine synthesis in cultured lymphoblasts were both intermediate between controls and lymphoblasts from patients with the Lesch‐Nyhan syndrome.