N-ACETYLATION PHENOTYPING WITH SULFAMETHAZINE IN AN IRANIAN POPULATION

The acetylation polymorphism is one of the most common inherited varia tions in the biotransformation of drugs and chemicals. Its association with drug toxicity and increased risk of developing certain diseases and certain types of chemically induced cancers has made it one of the oldest and best studied examples of pharmacogenetic conditions. N-Ace tylation of sulfamethazine was studied in 74 unrelated healthy Iranian volunteers. The frequency of slow acetylators, determined by using fr ee and total plasma sulfamethazine concentrations, was 78.4%. The mean acetylation ratio was 19.48% for slow acetylators, and the frequency of the recessive allele controlling slow acetylation was found to be 0 .88. This percentage is similar to that observed in various Arab count ries and higher than that observed in Europeans.