Paraoxonase 1 mutations in a Turkish population

Human serum paraoxonase 1 (PON1) catalyzes the hydrolysis of certain organo phosphate pesticides and nerve gases and so may alter significantly an indi vidual's susceptibility to the toxicity of these chemicals. Moreover, PON1 hydrolyzes lipid peroxides complexed to low density lipoproteins (LDL) and therefore it was suggested that PON1 may be one of the genes that is involv ed in the pathogenesis of cardiovascular diseases. Its activity shows inter individual and interethnic variability. At least two mutation sites, namely Gln192Arg (Q/R) and Leu55Met (L/M) were reported responsible for the varia tions in enzyme activity. The aim of the present study was to determine the frequency of these mutations in Turks and compare the results with other E uropean and Oriental populations. A total of 381 unrelated Turkish individu als were genotyped for Gln192Arg and Leu55Met polymorphisms by PCR-RFLP usi ng AlwI and NlaIII, respectively. Genotype distribution was QQ = 0.49, QR = 0.40, RR = 0.11, and LL = 0.52, LM = 0.39, MM = 0.09. Thus frequencies of high activity alleles R (Arg) and L (Leu) were found as 0.31 and 0.72, resp ectively. The frequency of these alleles was slightly higher in Turkish sub jects than other Caucasian populations but much lower compared to Oriental populations, (C) 1999 Academic Press.