Phosphoribosylpyrophosphate synthetase is elevated in fibroblasts from patients with the Lesch-Nyhan syndrome.

In subconfluent cultures of fibroblasts from patients with complete or partial deficiencies of hypoxanthine-guanine phosphoribosyltransferase, phosphoribosylpyrophosphate synthetase activity is elevated. The abnormally high catalytic activity of the synthetase appears to account for the overproduction of purines by the cultured mutant cells and presumably for that by the patients.