By comparing the differences of genotype, allele, and pertinent haplotype frequencies, we did not support a genetic association between CYP2E1 and AD in Han Taiwanese either by single allele tests or haplotype-based analyses.
Our findings suggest that the CAT c.-262C>T genetic polymorphism influences the susceptibility to alcohol dependence and severity of alcohol dependence, while CYP2E1 c.-1053C>T polymorphism influences the expression of obsessive-compulsive and anxiety symptoms.
We investigated whether variation in genes encoding cytochrome P450 2E1 (CYP2E1) or acetaldehyde-metabolising enzymes (ALDH1A1, ALDH2) might alter the risk of AD, with and without symptoms of anxiety, in a Cape population with mixed ancestry.
Thus, genes related to alcohol addiction, such as dopamine receptor D2 in the brain, or liver alcohol-metabolizing enzymes, such as alcohol dehydrogenase class I polypeptide B, cytochrome P450 2E1 and aldehyde dehydrogenase class 2, may vary from one individual to another.
Combined linkage and association indicate that sequence changes in or near CYP2E1 affect the level of response to alcohol providing a predictor of risk of alcoholism.
This documents the presence of a polymorphism of CYP2E1 that is overexpressed in alcoholic Otomies, in which the variant allele (A1 of CYP2E1/TaqI) is associated with increased susceptibility to alcoholism.
Case-control studies that have investigated the association between alcoholism and alcohol-induced liver damage and the ADH2, ADH3, CYP2E1, and ADLH2 polymorphisms have reported controversial or inconclusive results.
The polymorphisms of ADH2, ALDH2, and CYP2E1 were significantly different in Korean patients with alcoholism and Korean control subjects without alcoholism, but ADH3 and OPRM1 did not differ between the two groups.
Mexican-Americans have a low frequency of the protective alleles ADH1B(*)2 and ALDH2(*)2 and a relatively high frequency of CYP2E1 c2, which is associated with early onset alcoholism.(7).
In the present study, we have characterized these repeated sequences in the 5'-untranslated region of the CYP2E1 gene in Japanese subjects and North American white subjects and investigated whether these polymorphisms are associated with drinking habits and alcoholism.
The presentations were (1) Mutations in the exons, exon-intron junctions, and promoter regions of human CYP2E1 gene and alcoholism, by Fumio Nomura; (2) Genetic variability in alcohol metabolism and drinking habits in Japanese, by Shoji Harada; (3) Genetic studies of alcohol dependence using alcoholics with inactive ALDH2, by Susumu Higuchi; and (4) Alcohol consumption, apolipoprotein polymorphisms, and cardiovascular disorders, by Dharam P. Agarwal.
= 1, chi2 = 11.0, p < 0.001) difference in the CYP2E1 C gene frequency between alcohol dependents (0.41) and controls (0.28), suggesting that the C gene of CYP2E1 may be related to the risk of developing alcoholism in Japanese, whereas the frequency of the D gene was higher among controls than alcoholics.
Therefore, our results suggest that the allelic variations at the CYP2E1 gene locus also do not significantly affect the development of alcoholism or ALD in Han Chinese and Atayal natives of Taiwan.
The genotype distributions of CYTP2E1 did not differ among the three groups, indicating no allelic association of the c1/c2 polymorphism of CYTP2E1 with alcoholism.
There was no significant difference in C2 gene frequency between alcoholics (0.19) and nonalcoholics (controls) (0.20), whereas there was a significant difference in ALDH2 allele frequency, suggesting that, in Japanese, the C2 genotype of CYP2E1 may have nothing to do with the risk of developing alcohol dependence.