Under abnormal conditions the excessive reactive oxygen species generation results in genetic predisposition of various genes (as ADH, ALDH, CYP2E1, GSTT1, GSTP1 and GSTM1) involved in xenobiotic metabolic pathways, associated with susceptibility to different liver related diseases such as fibrosis, cirrhosis and hepatocellular carcinoma.
Patients with cirrhosis also had a higher frequency of the GSTM1 null genotype (71.1%) than HBV normal carriers (27.5%; OR 6.5, 95% CI 2.4-17.4) and the GSTM1 null genotype was more frequent in patients with chronic hepatitis (64.9%) than HBV normal carriers (27.5%OR 4.9, 95% CI 1.8-12.8).
Polymorphisms in glutathione S-transferases GSTM1, GSTT1 and GSTP1 and cytochromes P450 CYP2E1 and CYP1A1 and susceptibility to cirrhosis or pancreatitis in alcoholics.