BACKGROUND: The purpose of this study was to investigate genetic polymorphisms of cytochrome P4502E1 (CYP2E1) among healthy control and alcoholic Koreans in order to determine its relation-ship to the development of alcoholism. We also evaluate the diagnostic usefulness of carbohydrate deficient transferrin (CDT) in alcoholism. METHODS: The healthy control group included 72 males and 32 females. Patients with alcoholism included 53 males and 12 females who met DSM-IV diagnostic criteria (American Psychiatric Asso-ciation, 1994) and were admitted to alcoholism treatment units. Rsa I and Pst I restriction fragment length polymorphisms of CYP2E1 gene PCR product determined the genotype of CYP2E1. The serum level of CDT was analyzed by Behring Nephelometer II using %CDT turbidimetric immunoassay kit. RESULTS: The prevalence of CYP2E1 genotypes was 74.0% for type A, 23.1% for type B, and 2.9% for type C in the 104 healthy subjects, and 93.8% for type A and 6.2% for tyupe B in the 65 patients with alcoholism. The allele frequency of c1 and c2 of CYP2E1 was 85.6% and 14.4%, respectively, in the control group and 96.9% and 3.1%, respectively, in the alcoholics. The %CDT range in healthy controls and alcoholics was 0-7.8% and 3.1-21.1%, respectively. The serum CDT level in the patients with alcoholism (14.4 +/-4.5, mean +/-SD) was higher than that of healthy controls (3.2 +/-1.2, ) (P<0.05). The sensitivity, specificity, positive predictive value, negative predictive value, false positive rate, false negative rate, and test efficiency of %CDT were 85.1%, 93.3%, 88.7%, 90.6%, 6.7%, 15.4%, and 89.9%, respectively. CONCLUSIONS: There was a significant difference in frequencies of CYP2E1 genotype (P=0.001) and allele (P=0.003) between patient with alcoholism and control group, and the absence of CYP2E1 c2 allele was associated with alcoholism. Assessment of CDT yielded useful and objective informa-tion in the diagnosis and identification of alcoholism.