Polymorphisms in the DNA repair gene XRCC1 and susceptibility to alcoholic liver cirrhosis in older Southeastern Brazilians.
The population of Southeastern Brazil has a very high mortality rate from liver cirrhosis, a disease that is considered an irreversible pre-malignant condition. This is largely due to the high prevalence of alcohol abuse in the region. Chronic alcohol consumption is associated with the production of free radical intermediates that can cause several DNA lesions. Reduced repair of these DNA lesions would, therefore, constitute a significant risk factor for liver cirrhosis and subsequent cancer. Recently, a number of polymorphisms in several DNA repair genes have been discovered, and it is possible that these polymorphisms may affect DNA repair capacity and thus modulate susceptibility to the disease. In this study, we tested the hypothesis that polymorphisms in the DNA repair gene XRCC1 are associated with increased risk of liver cirrhosis in Southeastern Brazilians. We conducted a pilot case-control study of 97 liver cirrhosis cases and 96 controls (matched for age, sex, and ethnicity) to investigate the role of two allelic variants coding for amino acid changes in the XRCC1 gene (the Arg194Trp and the Arg399Gln polymorphisms). Overall, we observed a 1.8-fold increase in the relative risk of liver cirrhosis associated with the 399Gln allele (either the heterozygous Arg/Gln or the homozygous Gln/Gln genotypes). The adjusted odds ratio (OR) was 1.82 (95% confidence limit (CL) 1.10-3.30). The relative risk appears to be highest among the Mestiso ethnic group (OR 2.60, 95% CL 0.92-7.34). There was a significant association between the 399Gln polymorphism and the risk of liver cirrhosis in older individuals over the age of 45 years (OR 2.70 (95% CL 1.14-6.48) compared to an OR of 1.24 (95% CL 0.55-2.78) for those under 45 years of age. No association was observed between the XRCC1 194Trp polymorphism and risk of liver cirrhosis. These preliminary results suggest that the XRCC1 399Gln polymorphism may be a significant risk modifier for alcoholic liver cirrhosis and justifies additional studies in that direction.
Rossit
Andréa Regina B
AR
Laboratory of Molecular Epidemiology and Mutagenesis, University of São Paulo State, São José do Rio Preto, Brazil.
Cabral
Isabel Rosa
IR
Hackel
Christine
C
da Silva
Rita
R
Froes
Nívea D T Conforti
ND
Abdel-Rahman
Sherif Z
SZ
D000328:Adult; D000367:Age Factors; D000483:Alleles; D001938:Brazil; D019363:Cytochrome P-450 CYP1A1 / Q000235:genetics; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008104:Liver Cirrhosis, Alcoholic / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D000076105:X-ray Repair Cross Complementing Protein 1
D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; D019363:Cytochrome P-450 CYP1A1