Genotype of ethanol metabolizing enzyme genes by oligonucleotide microarray in alcoholic liver disease in Chinese people

Objective To explore the relationship between genetic polymorphisms of the ethanol metabolizing enzymes and the occurrence of alcoholic liver disease (ALD).Methods Sixty-five healthy male controls and 165 alcoholisms (including 122 ALD patients and 43 male alcohol abusers without liver complications defined as alcohol-dependent) were analyzed by polymerase chain reaction and hybridized with oligonucleotide microarray to detect the polymorphisms of the ethanol metabolizing enzymes genes.Results The frequencies of alcohol dehydrogenase gene 2*1 (ADH2*1) allele were shown as 37.69%, 46.51% and 59.02% in control, alcohol-dependent and ALD groups respectively; while those of ADH2*2 allele were shown as 62.31%, 53.49% and 40.98% respectively.No ADH2*3 was detected in any of the subjects. The frequency of ADH2*1 was significantly higher in alcoholisms (ALD group and alcohol-dependent group) than in healthy controls (P<0.01), and significantly higher in ALD group than in alcohol-dependent group (P<0.05).The frequency of ADH3*2 was significantly higher in alcohol-dependents than in healthy controls (P<0.05).The frequencies of ALDH2*2 allele mutation were significantly lower in alcoholisms than that in the healthy controls, and the deference between ALD group and alcohol-dependent group was significant.No homozygotes for the mutant ALDH2*2 allele were found in either alcoholic groups.Conclusions Polymorphic ADH2, ADH3 and ALDH2 genes can affect the propensity for alcohol drinking in Chinese.The alleles of ADH2*2, ADH3*1 and ALDH2*2 are most likely to play a protective role against excessive consumption.ADH2*2 and ALDH2*2 may contribute to susceptibility for ALD.