The spectrum of hypoxanthine-guanine phosphoribosyltransferase deficiency

The spectrum of clinical manifestations of hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) deficiency is presented by reference to eight patients from five kindred. These patients illustrate the range of associated neurological findings, together with the variety of presentation and complications due to the associated over-production of urate. Such a study permits the development of a unifying concept between primary over-production of urate and the subsequent development of uric acid crystalluria and calculi, hyperuricaemia, gouty arthritis, and renal insufficiency. Comparison is also made between the clinical manifestations and the levels of HGPRTase activity assayed in red cell haemolysates. Although it might have been expected that the degree of enzyme deficiency would parallel the clinical manifestations, no significant correlation was found between the clinical severity of the condition and the enzyme activity in erythrocytes. It is suggested that additional factors besides the actual level of HGPRTase activity present in red cells are important in determining the severity of the neurological lesions and of the urate abnormality in this condition