[Genetic polymorphism in Gilbert-Meulengracht syndrome (GMS)]

N-Acetylation and debrisoquine hydroxylation phenotypes were determined in 54 patients with Gilbert's syndrome and in 247 (sulfamethazine) and 76 (debrisoquine) non-related healthy volunteers, respectively. 40 (74.1%) of the patients and 135 (54.7%) of healthy volunteers were slow acetylators (chi 2 = 6.87). In patients, the cumulative urinary excretion (CUE) of sulfamethazine (0-6 hours) was significantly reduced. No differences between the debrisoquine poor metabolizers were observed: Gilbert's syndrome 5/54 (9.3%), healthy volunteers 5/76 (6.6%). The metabolic ratios were similar in both groups as well as the CUE of debrisoquine and its metabolite. Gilbert's syndrome seems to be related in some way to N-acetylation but not to debrisoquine hydroxylation polymorphism.