Specifically, it catalyzes the conversion of inosine to hypoxanthine and guanosine to guanine (both guanine and hypoxanthine will be made into xanthine which will then become uric acid). A deficiency of it leads to buildup of elevated deoxy-GTP (dGTP) levels resulting in T-cell toxicity and deficiency. In contrast to adenosine deaminase deficiency (another deficiency of purine metabolism), there is minimal disruption to B cells.
Specifically, it triggers the conversion of inosine to hypoxanthine and guanosine to guanine (both resulting in xanthine, which is then converted into uric acid). A lack of it leads to an accumulation of elevated deoxy-GTP (dGTP) levels, causing T-cell toxicity and deficiency. In contrast to adenosine deaminase deficiency (another purine metabolism disorder), there is minimal disruption to B cells.