Corradino Motti | PubMed Health

PubMed2002

Apolipoprotein E genotyping: a comparative study between restriction endonuclease mapping and allelic discrimination with the LightCycler.

BACKGROUND: The apolipoprotein E (apo E) polymorphism is associated with the risk of developing cardiovascular disease and the risk and the time of onset of Alzheimer's disease. Therefore, the interest in apo E genotyping is high, both for epidemiological research and for the purpose of diagnosing dyslipidemia or dementia. The aim of our study was to compare and evaluate two different methods for apo E genotyping, both on the basis of polymerase chain reaction (PCR). METHODS: Genomic DNA of 197 subjects was extracted from whole blood. The first method involved DNA amplification performing a PCR using specific primers and endonuclease restriction mapping. The second one was a DNA assay that used real-time PCR on the LightCycler instrument (Roche). RESULTS: We obtained a 100% concordance between the two methods and we found a relative allelic frequency distribution typical for an Italian population. CONCLUSIONS: The LightCycler (LC) allelic discrimination method for apo E genotyping seems to be rapid, simple and accurate, suggesting a possible successful use of this method for diagnostic purposes.

Alleles↗

PubMed2002

The Arg allele in position 192 of PON1 is associated with carotid atherosclerosis in subjects with elevated HDLs.

Human serum paraoxonase (PON1) is an HDL-associated enzyme involved in the protection of lipoproteins from oxidation. A polymorphism at position 192 (Gln/Arg) influences its activity in a substrate-dependent manner. The aim of the present study was to evaluate, in vivo, the contribution of the PON1-192 polymorphism to the protective effect of HDLs. Three hundred and forty seven subjects in the upper and lower decile of sex-specific HDL cholesterol distribution were selected from participants in a cardiovascular disease prevention study. PON1 genotypes were determined by PCR amplification and restriction analysis. Blood pressure, height, weight, smoking and alcohol habits, as well as the presence of familial or personal history of CHD were recorded. Plasma lipids and blood glucose were measured by routine enzymatic methods. As a measure of antiatherogenic HDL effect, carotid atherosclerosis was assessed by ultrasonography. Allele and genotype frequencies did not differ significantly between low- and high-HDL groups. Similarly, no significant difference was observed among genotypes in all variables studied. Subjects with Gln/Arg or Arg/Arg had more carotid abnormalities than Gln/Gln with an adjusted odds ratio (OR) of 3.27 (95% CI, 1.61-6.64, P=0.001) for abnormal carotid score. Stepwise logistic regression analysis showed that in the whole population age and presence of low-HDL were the only independent predictors for abnormal carotid score. In low-HDL, age was the only independent predictor entered into the model (OR 1.09/year, P<0.0001); in high-HDL, age entered first (OR, 1.07/year, P=0.001), followed by the presence of Gln/Arg or Arg/Arg (OR, 2.94, 95% CI, 1.47-5.91, P=0.002). In conclusion, in subjects with low levels of HDL cholesterol, carotid atherosclerosis is not related to PON1-192 polymorphism. On the other hand, in subjects with elevated concentration of HDL cholesterol, the presence of carotid atherosclerosis is significantly associated with the arginine variant in position 192 of the PON1 gene.

Adult↗