Relationship of LEU-MET (55) and GIN-ARG (192) polymorphisms of the paraoxonase 1 (PON1) gene and coronary artery disease risk

Objectives: Paraoxonase (PON1) is a High-Density Lipoprotein (HDL)- associated esterase that hydrolyses lipo-peroxides. PON1 has attracted attention as a protective factor against oxidative modification of LDL and may therefore play an important role in the prevention of the atherosclerotic process. Two polymorphisms have been extensively studied: a Leucine (L allele) to Methionine (M allele) substitution at codon 55, and a Glutamine (A allele) to Arginine (B allele) substitution at codon 192. Methods: We have examined these two amino acidic changes in 120 patietns and 102 controls. Genotypes were determined by polymerase chain reaction (PCR) and restriction mapping with Alw I and Nla III enzymes. Results: A total of 67 (% 55.8), 48 (% 40.0) and 5 (% 4.2) patient subjects had Q/Q, Q/R and R/R genotypes, and 8 (% 6.8), 56 (% 46.6) and 56 (% 46.6) control subjects had M/M, M/L and L/L genotypes respectively. Smoking, hypertension, diabetes mellitus, family history, body mass index, plasma levels of LDL and total cholesterol were significantly important risk factors for coronary artery disease (CAD). In this study, we found that the M/L55 polymorphism of PON1 are associated with CAD, and the Q/R192 polymorphism is not a major risk factor in susceptibility to CAD in the our population.Key Words: Atherosclerosis, Paraoxonase, Gene, Polymorphism.