Anna Balcerzyk

Synergistic effect between polymorphisms of PPARA and ABCA1 genes on the premature coronary artery disease.

Objective — Progression of atherosclerosis, the main reason of cardiovascular diseases, depends on multiple genetic and environmental factors. Polymorphic variants of genes involved in the lipids metabolism may genetically differentiate human populations and determine a susceptibility to the disease. The aim of the present study was to evaluate a possible interaction between R219K polymorphism of ABCA1 gene and G>C polymorphism in intron 7 of PPARA gene in determining the risk of the CAD. Methods — We studied 358subjects: 178patients with angiographically confirmed CAD and 180 blood donors without history of CAD. Polymorphisms were genotyped using the PCR-RFLP method. Results — In spite of a small or no correlation between single polymorphism and CAD we observed that the frequencies of AA+GC, CC genotype pattern (ABCA1 and PPARA gene) were significantly higher in CAD group than in controls. OR values were especially high in multiple logistic regression and were higher for male subgroups.The synergy index value equals 3.98 and indicates a quite strong synergistic effect between the analysed polymorphisms. We also observed that C allele carriers of PPARA gene had a significantly lower total and LDL-cholesterol level. Conclusion — The present study shows that R219K polymorphism of ABCA1 gene and G>C polymorphism in intron 7 of PPARA gene act cumulatively and synergistically in determining the risk of premature CAD.

CYP3A5∗3 and C3435T MDR1 Polymorphisms in Prognostication of Drug-Resistant Epilepsy in Children and Adolescents

Drug-resistant epilepsies still remain one of the most profound problems of contemporary epileptology. Several mechanisms of drug resistance are possible; among them, genetic factors have a prominent place. Much importance is attached to genes, which encode enzymes that metabolize antiepileptic drugs CYP 3A, which belong to the family of cytochromes P450 and the genome of multidrug resistance, such as multidrug resistance 1 (MDR1) that expresses P-glycoprotein (P-gp), a drug transporter protein. The aim of the study was to assess the relation between polymorphism of gene CYP3A5 and polymorphism C3435T of MDR1 gene with the occurrence of focal, drug-resistant epilepsy in children and youths up to 18 years of age. The study comprised 85 patients, and their age range was from 33 months to 18 years of age, suffering from epilepsy, partly responding well to treatment, partly drug resistant. The polymorphism of both genes has been analysed using the PCR-RFLP method. The study failed to corroborate association between polymorphism CYP3A5∗3 and C3435T polymorphism in MDR1 gene and pharmacoresistant epilepsy. The results of our research do not confirm the prognostic value of the polymorphisms examined in the prognostication of drug resistance in epilepsies.

APOE Gene ε Polymorphism Does Not Determine Predisposition to Ischemic Stroke in Children

Ischemic stroke in children is relatively rare, but it remains an important medical problem. Previous studies on Polish children have implicated dyslipidemias as significant risk factors in stroke. To search for genetic factors associated with the disease, the possible association between apolipoprotein E gene epsilon polymorphism and childhood stroke was evaluated. The study population consisted of 243 individuals: 72 children with ischemic stroke and 100 of their biological parents and 71 children without any symptoms of stroke. The apolipoprotein E gene epsilon polymorphism was genotyped using restriction fragment length polymorphism methodology. To analyze the possible association between this polymorphism and stroke, the transmission disequilibrium test and the case-control model were used. No preferential distribution of any allele from parents to the affected children was observed. There were also no significant differences in genotype and allele distribution between patients and control subjects. Study findings did not confirm that epsilon polymorphism of the apolipoprotein E gene is a risk factor of ischemic stroke in children.

Protective effect of R allele of PON1 gene on the coronary artery disease in the presence of specific genetic background.

Background: Genetic susceptibility to CAD may be determined by polymorphic variants of genes encoding isoforms involved in the processes important in the pathogenesis of atherosclerosis, including lipids disorders. Participation of single polymorphic variants is relatively small, however its significance may increase in the presence of specific genetic or environmental background. Aim: The aim of the study was an evaluation a possible association between single polymorphic variants of PON1, APOE, ABCA1 and PPARA genes and CAD and looking for specific multigene genotype patterns which differentiate study groups. Materials and methods: We studied 358 subjects:178 patients with angiographically confirmed CAD and 180 blood donors without history of CAD. Polymorphisms were genotyped using PCR-RFLP method. Results: We observed statistically significant differences in the frequencies of R allele and R allele carriers of PON1 gene between CAD and controls. The distribution of genotypes and alleles of other analyzed genes did not differentiate the study groups, however the presence of specific genotypes (APOE– ɛ3ɛ3, ɛ3ɛ2, ABCA1 – AG, PPARA – GG) increased the protective effect of R allele. Conclusion: The present study revealed an independent protective association between carrier-state of PON1 R allele and CAD. This protective effect was especially strong in the presence of specific genotype arrangements of other analyzed genes.

The CYBA gene A640G polymorphism influences predispositions to coronary artery disease through interactions with cigarette smoking and hypercholesterolemia.

The CYBA gene encodes the p22phox peptide, an essential subunit of vascular NADPH oxidases. The aim of the study was to analyze potential interactions between CYBA gene A640G polymorphism and traditional risk factors of atherosclerosis. We studied 320 subjects: 160 patients with coronary artery disease (CAD) and 160 controls. The results of interactions were interpreted on the basis of synergy index values (SI, SIM). The 640G allele interacted with cigarette smoking (SI = 2.02, SIM = 2.32). Even greater increase of the CAD risk was found whenever the 640G allele interacted with both smoking and hypercholesterolemia (SI = 2.70, SIM = 3.60). The results suggest that the A640G polymorphism may influence individual predispositions to CAD through interactions with smoking and hypercholesterolemia.

The C242T polymorphism of the gene encoding cytochrome b-245 alpha is not associated with paediatric ischaemic stroke: family-based and case-control study.

BACKGROUND AND PURPOSE Reactive oxygen species play an important role in the physiology and pathology of cerebral arteries, including ischaemic stroke. The cytochrome b-245 alpha gene (CYBA) encodes cytochrome b-245 alpha light chain (p22phox peptide), a critical element of NAD(P)H oxidases, the most important source of superoxide anion in the cerebral arteries. To search for genetic factors associated with paediatric ischaemic stroke, the possible association between CYBA gene C242T polymorphism and the disease was evaluated. MATERIAL AND METHODS The study group consisted of 238 individuals: children with ischaemic stroke (n = 70), their biological parents (n = 118) and children without any symptoms of stroke (n = 50). The C242T polymorphism was genotyped using polymerase chain reaction - restriction fragment length methodology. To evaluate the possible association between polymorphism and stroke, the transmission disequilibrium test and the case-control method were applied. RESULTS The C242 allele was transmitted more frequently than 242T (62.2% vs. 37.8%) but observed frequencies did not differ significantly from expected (p = 0.10). There were also no significant differences in allele and genotype distribution between patients and control subjects (patients: CC - 50.0%, CT - 38.6%, TT - 11.4% vs. controls: CC - 52.0%, CT - 36.0%, TT - 12.0%). CONCLUSIONS The study did not show that the C242T polymorphism of the CYBA gene is a risk factor of ischaemic stroke in children.

Combined "pro-atherosclerotic" variants of the ACE and APOE genes increase the risk of the coronary artery disease associated with the presence of cigarette smoking.

Objective — Cigarette smoking increases the synthesis of angiotensin-I converting enzyme (ACE) and induces oxidative modifications of the apolipoprotein E (apo E).Thus we explored the gene-environment interactions between APOE gene epsilon and ACE gene insertion/deletion polymorphisms and cigarette smoking in coronary artery disease (CAD) patients. Methods — We analysed 360 subjects: 171 CAD patients and 189 blood donors without a history of cardiovascular diseases. ACE and APOE polymorphisms were genotyped using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods, respectively.To determine gene-environment interactions, epidemiological methodology was used. Results — The ACEDD genotype was a rather weak risk factor of CAD in the analysed population (OR = 1.87, P= 0.01).The differences in allele and genotype distribution of the APOE polymorphism were not statistically significant.The carriers of the combined genotype ACEDD + APOEɛ4ɛ4,ɛ3ɛ4,ɛ2ɛ4 were more frequent in patients, however, the differences were on the bound of statistical significance (P= 0.08). Logistic regression analysis showed that the ACEDD + apo Eɛ4ɛ4,ɛ3ɛ4,ɛ2ɛ4 cigarette smokers were much more frequent in the CAD group (OR = 11.68, 95%CI; 1.52-246.43, P= 0.009).We confirmed these results using the 4 ≈ 2 table approach and we found a synergistic effect of the ACEDD + APOEɛ4ɛ4,ɛ3ɛ4,ɛ2ɛ4 combined genotype and cigarette smoking (SI = 10.52, SIM = 6.09). Conclusions — We demonstrated the existence of the synergistic effect between cigarette smoking and the contemporaneous carrier-state of APOE e4 and ACED alleles which increased the risk of CAD to a large extent.

Polymorphisms of genes encoding coagulation factors II, V, VII, and XIII in relation to pediatric ischemic stroke: family-based and case-control study.

Background:The investigation of a possible association between the FII, FV, FVII, and FXIII genes polymorphisms and pediatric ischemic stroke (IS). Methods:The study group consisted of 392 individuals, including 81 children with IS, their biological parents (n=162), and 149 control children. The polymorphisms were genotyped using polymerase chain reaction-restriction fragments length polymorphism method. The relation between analyzed polymorphisms and the disease was tested by 2 independent methods: family-based association test—transmission/disequilibrium test (TDT) and classic case-control model. Results:We did not observe any preferential distribution of any analyzed allele from parents to the affected children. For the FVII gene polymorphism, there was a trend toward a higher frequency of the R allele. In a case-control model, the differences between the patients and controls in the frequency of the Q allele, Q allele carriers, and RR homozygotes lay close to the border of statistical significance (P=0.08). There were no significant differences in genotype and allele distribution between patients and controls in case of other polymorphisms. Conclusions:Analyzed polymorphisms of coagulation factors are not significant determinants of pediatric IS in the studied population; however, these findings require a confirmation in a larger group of participants.

Methylenetetrahydrofolate reductase gene A1298C polymorphism in pediatric stroke--case-control and family-based study.

Moderate hyperhomocysteinemia is one of the risk factors of pediatric stroke. Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme, which regulates homocysteine metabolism, and some polymorphisms of gene encoding this enzyme are associated with a decreased activity of the enzyme. The aim of the study was to assess an association between the A1298C polymorphism and pediatric stroke. We also evaluated a possible synergistic effect of A1298C and C677T polymorphisms of this gene. The study group consisted of 88 children after ischemic stroke, 142 of their parents and 111 controls. The A1298C polymorphism was genotyped using the restriction fragment length polymorphism method. We used 2 study designs: a case-control model and a family-based association test. The Statistica 7.1 and EpiInfo 6 softwares were used in all analyses. We did not observe any statistically significant differences either in the transmission of the A allele in the family-based test or in the frequency of the A allele in the patients group compared with the controls. We also did not notice any significant additive or synergistic effects between the A1298C and C677T polymorphisms. An analysis of the results obtained in this study and a critical review of previously published studies indicate that the A1298C polymorphism of the MTHFR gene is not related to ischemic stroke in children.

The rs2516839 Polymorphism of the USF1 Gene May Modulate Serum Triglyceride Levels in Response to Cigarette Smoking.

Single nucleotide polymorphisms (SNPs) of the USF1 gene (upstream stimulatory factor 1) influence plasma lipid levels. This study aims to determine whether USF1 SNPs interact with traditional risk factors of atherosclerosis to increase coronary artery disease (CAD) risk. In the present study serum lipid levels and USF1 gene polymorphisms (rs2516839 and rs3737787) were determined in 470 subjects: 235 patients with premature CAD and 235 controls. A trend of increasing triglycerides (TG) levels in relation to the C allele dose of rs2516839 SNP was observed. The synergistic effect of cigarette smoking and C allele carrier state on CAD risk was also found (SIM = 2.69, p = 0.015). TG levels differentiated significantly particular genotypes in smokers (1.53 mmol/L for TT, 1.80 mmol/L for CT and 2.27 mmol/L for CC subjects). In contrast, these differences were not observed in the non-smokers subgroup (1.57 mmol/L for TT, 1.46 mmol/L for CT and 1.49 mmol/L for CC subjects). In conclusion, the rs2516839 polymorphism may modulate serum triglyceride levels in response to cigarette smoking. Carriers of the C allele seem to be particularly at risk of CAD, when exposed to cigarette smoking.