Cytochrome P450 2E1 high activity polymorphism in alcohol abuse and end-organ disease

Abstract

Aim: To investigate a possible role for a recently identified polymorphism in the gene of cytochrome P450 2E1, the presence of which is associated with high activity of the enzyme.

Methods: Two hundred and thirty-nine alcohol consumers, ICD 10.1/.2 (ALC), and 208 normal controls were studied. PCR amplification of the CYP2E1 gene region was performed to assess polymorphic variation. Fisher's exact test was used to assess the data.

Results: Twelve normal controls (5.8%) possessed the insertion. Five ALC (2.1%) had the insertion; of these 2 of 144 with alcohol induced chronic pancreatitis, none of 28 with alcoholic liver disease and 3 of 67 without end-organ disease had the polymorphism. A significantly Lower frequency of subjects possessed the insertion than normal controls [P=0.049 (genotype analysis P=0.03)]. To further assess, if there was a relationship to alcohol problems per se or end-organ disease, we compared patients with alcohol induced end-organ disease vs alcoholic controls without end-organ disease vs normal controls which again showed a significant difference [P=0.045 (genotype analysis, P=0.011)], further sub-group analysis did not identify which group(s) accounted for these differences.

Conclusion: We have shown the frequencies of this high-activity polymorphism in alcohol related patient groups for the first time. The frequency is significantly less in alcoholics than normal controls, as with high activity polymorphisms of alcohol dehydrogenase. The biological significance, and whether the relevance is solely for alcoholism or is there a relationship to end-organ disease, would benefit from the assessment in the populations with a greater frequency of this polymorphism.

Figure 1

A: Agarose gel showing wild type homozygotes (633 bp, lanes 1, 3, 5–7) and a heterozygote for the insertion polymorphism (729 bp, lane 4). Run alongside a molecular weight marker (M); B:Agarose gel showing wild type homozygotes (633 bp, lanes 1–3 and 5) and a heterozygote for the deletion polymorphism (585 bp, lane 4). Run alongside a molecular weight marker (M).