Rarity of X-Linked Partial Hypoxanthine-Guanine Phosphoribosyltransferase Deficiency in a Large Gouty Population

In a survey of 425 cases of hyperuricemia with gouty arthritis or uric acid stone, or both, we found partial deficiency of H-G PRTase, a newly recognized cause of these manifestations, in only 7 subjects, of whom 5 were members of one family. The prevalence in this series was thus 1.6%, which is probably higher than in the gouty population at large because this study included a disproportionately large number of severely afflicted patients. Transmission was through heterozygous, asymptomatic mothers and was expressed only in sons, consistent with X-linkage. Six of the seven hemizygotes detected conformed to previous reports in having very low erythrocyte H-G PRTase activity (about 0.1% to 1% of normal) and increased urinary hypoxanthine to xanthine ratios, usually with relatively early onset of severe symptoms. In the seventh case erythrocyte H-G PRTase activity was about 30% of normal, with an accompanying increase in the urinary hypoxanthine to xanthine ratio. This patient had late onset of moderately severe recurrent gouty arthritis.