807C/T polymorphism in the platelet glycoprotein Ia gene in young patients with ischemic stroke of undetermined etiology

Association of BglII Polymorphism in ITGA2 and (894G/T and -786T/C) Polymorphisms in eNOS Gene With Stroke Susceptibility in Tunisian Patients α2 Gene Polymorphism in α2β1 Integrin and eNOS Gene Variants and Stroke

BACKGROUND

This study investigated the association of BglII polymorphism in α2β1 integrin gene (ITGA2) and eNOS (894G/T and -786T/C) polymorphisms with ischemic stroke (IS) in Tunisian patients.

METHODS

The study comprised 210 patients with IS and 208 controls. The genotypes of the BglII polymorphism in ITGA2 and eNOS (894G/T and -786T/C) polymorphisms were determined using the PCR-RFLP. The χ² test was used and the genotype data comparison included heterozygous groups. Haplotype estimation and multiple logistic regression analysis were performed to analyze the significance of polymorphisms.

RESULTS

The genotype distribution of the BglII polymorphism was significantly different between cases and controls (p < 0.004). This polymorphism was associated with the risk of IS (OR = 3.38, p < 0.001) for the BglII(+/+) genotype. Likewise, the genotype distributions of eNOS (894G/T and -786T/C) polymorphisms were significantly different between the two groups (p < 0.005 and p < 0.01, respectively). The 894G/T polymorphism increased the risk of IS for the TT genotype (OR = 2.23, p < 0.008) and the GT genotype (OR = 1.74, p < 0.009). In addition, the -786T/C variant in the eNOS gene was a risk factor for IS for CC homozygous (OR = 2.52, p < 0.005). T-C Haplotype (OR = 3.06) from combination of the eNOS (894G/T and -786T/C) and T-C-BglII(+) haplotype (OR = 2.76) from combination of eNOS and ITGA2 polymorphisms represented high risks for IS.

CONCLUSIONS

This study suggests that the BglII variant in ITGA2 is associated with IS susceptibility. Furthermore, the 894G/T and -786T/C polymorphisms in the eNOS gene may be considered as genetic risk factors for IS in the Tunisian population.

Platelet glycoprotein gene Ia C807T, HPA-3, and Ibα VNTR polymorphisms are associated with increased ischemic stroke risk: Evidence from a comprehensive meta-analysis

Background/aims

Platelet glycoproteins play a crucial role in the initial stage of thrombus formation and may contribute to the pathophysiology of atherosclerosis. Polymorphisms in glycoprotein genes alter the function of the protein, possibly leading to increased risk of ischemic stroke. However, previous genetic association studies that examined the relationship between glycoprotein genes polymorphisms and ischemic stroke have yielded inconsistent results. This study aimed to evaluate the association between glycoprotein genes and ischemic stroke by the application of meta-analysis.

Methods

Relevant studies were identified by an extensive search through databases. The quality of included studies was assessed independently using the Newcastle–Ottawa Scale. Allele and genotype frequencies for each included study were extracted. The odds ratio (OR) with 95% confidence interval (95%CI) was calculated using a random-effects or fixed-effects model. Q statistic was used to evaluate homogeneity, and a meta-regression model was used to explore the study-level variables and to describe the heterogeneity in included studies. Egger’s test and funnel plot were used to assess publication bias.

Results

A total of 60 studies (9 polymorphisms) were included and identified in the current meta-analysis. The Newcastle–Ottawa Scale scores ranged from 7 to 9 except for two studies with Newcastle–Ottawa Scale scores of 6. The T allele or TT genotype of the glycoprotein Ia C807T polymorphism were associated with an increased susceptibility to ischemic stroke in combined population (807T allele: OR, 95%CI: 1.24, 1.03–1.50, p = 0.02) or Asian populations (807T allele: OR, 95%CI: 1.31, 1.10–1.54, p = 0.002 and 807TT genotype: OR, 95%CI: 1.53, 1.13–2.08, p = 0.006, respectively), and the Ser allele of HPA-3 was associated with increased risk of ischemic stroke in combined population or in Asians (OR, 95%CI: 1.21, 1.04–1.40, p = 0.01 or 1.54, 1.18–2.01, p = 0.001). Of note, the Ser/Ser genotype was more common in Asians (OR, 95%CI: 2.09, 1.40–3.13, p < 0.001). For glycoprotein Ibα variable number tandem repeat, only B allele showed a mild significant association with ischemic stroke risk in combined population or in Caucasians (OR, 95%CI: 2.17, 1.04–4.55, p = 0.04 or 1.79, 1.02–3.13, p = 0.04). There was no significant association between HPA-1, HPA-2, HPA-4, HPA-5, glycoprotein Ibα-5 T/C as well as Ia G873A polymorphisms and increased risk of ischemic stroke.

Conclusions

We found that glycoprotein Ia C807T T allele or the TT genotype, the Ser-allele of HPA-3 and B allele of glycoprotein Ibα variable number tandem repeat polymorphisms were associated with increased risk for ischemic stroke. Future studies with larger sample sizes will be necessary to confirm the results. In addition, analyses of ischemic stroke subtypes and gene–gene and gene–environment interactions are warranted.

Common genetic variants in platelet surface receptors and its association with ischemic stroke

Ischemic stroke has been named one of the leading causes of death worldwide. Whereas numerous biological mechanisms and molecules were found to be associated with stroke, platelets are particularly contributive to its pathogenesis. Recent data indicate considerable variability in platelet phenotype which accounts for differences in platelet surface receptor function, count and reactivity. These features collectively influence both the events leading to a disease and effectiveness of antiplatelet therapies. Consequently, genetic variants predisposing to cerebrovascular diseases can be sequenced using a wide array of techniques and become a useful tool in clinical setting. In this review, we provide an outline of common platelet polymorphisms that impose risk on ischemic stroke development and should be evaluated as targets to improve treatment. As study results are often inconsistent, partly due to differences in demographic characteristics between study populations and the fact that the functional impact of these variants has been relatively small, we conclude that both rare, low-frequency and common variants might account for genetic contribution on abnormal platelet response to antiplatelet drugs.

Genetic polymorphism of ITGA2 C807T can increase the risk of ischemic stroke

BACKGROUND

The role of genetic variants in the pathogenesis of stroke has not been fully elucidated. Several studies have been examined the association of the Integrin alpha2 (ITGA2) gene-C807T (rs1126643) polymorphism with ischemic stroke susceptibility. However, the results of these studies are inconsistent. In order to explore this association more deeply, we performed a meta-analysis.

METHODS

We collected case-control studies concerning the relationship between the C807T polymorphism and ischemic stroke, and odd ratios (OR) with corresponding 95% confidence intervals (CI) were used to describe the relationships. Inconsistency index (I(2)) and Cochran's Q statistic were used to check heterogeneity. Publication bias was tested by funnel plots and Egger's test.

RESULTS

Fifteen studies with 2242 cases and 2408 controls were included. Our meta-analysis results indicated an association between the C807T polymorphism and the risk of ischemic stroke in the overall population, Asians and the subgroup of hospital-based people. However, statistically association was not observed for Caucasians and non-hospitalized individuals.

CONCLUSIONS

The ITGA2 gene C807T polymorphism may be a susceptible predictor of the risk of ischemic stroke. More data are needed to elucidate the relationship further.

Gene polymorphisms and risk of adult early-onset ischemic stroke: A meta-analysis

INTRODUCTION

Genetic studies restricted to young adult ischemic stroke patients may help in excluding the potentially confounding variables encountered with advanced age; thus, allowing a more precise risk evaluation derived from the inherited mutations alone. Through meta-analysis, this study was conducted to determine the genetic risk contributed by each susceptibility gene polymorphism, particularly in adult early-onset ischemic stroke patients.

MATERIALS AND METHODS

Electronic databases were searched for all the case-control studies relating to any candidate genes for ischemic stroke. The range of age was 18-50 years for cases. Fixed or random effects model was used depending on the heterogeneity between studies.

RESULTS

Twenty-six studies were finally included in this meta-analysis; these studies focused on 7 candidate genes. A significant but modest association was identified for 2 polymorphisms, namely, methylenetetrahydrofolate reductase (MTHFR) C677T (OR = 1.44, 95% CI = 1.14-1.80) and apolipoprotein E (ApoE) epsilon2-4 (OR = 2.53, 95% CI = 1.71-3.73). Although the pooled analysis for platelet glycoprotein Ia (GPIa) C807T showed a positive association (OR = 1.50, 95% CI=1.10-2.05), the Egger's test indicated the existence of publication bias (t=5.27, P>|t|=0.034).

CONCLUSIONS

Genetic abnormalities specific to homocysteine and lipid metabolism increase the risk for ischemic stroke at an early age. These data may offer important implications for future genetic association studies for stroke.