Identification of genetic contribution to ischemic stroke by screening of single nucleotide polymorphisms in stroke patients by using a case control study design

Genetic and epigenetic polymorphisms of eNOS and CYP2D6 in mainland Chinese Tibetan, Mongolian, Uygur, and Han populations

Cytochrome P450 2D6 (CYP2D6) and endothelial nitric oxide synthase (eNOS) are important in the cardiovascular disease susceptibility and drug response. The methylation of cytosine in the promoter of genes could influence expression. The interindividual differences of drug response could only be explained partly by the polymorphisms of drug disposition genes. This study was aimed to investigate the genetic and epigenetic polymorphisms of CYP2D6 and eNOS in Chinese Tibetan, Mongolian, Uygur, and Han volunteers. Blood samples were collected from 842 unrelated Chinese healthy subjects (323 Tibetan, 134 Mongolian, 162 Uygur, and 223 Han) for genotyping and part of the DNA samples were subjected to cytosine methylation analysis. Significant genetic and epigenetic interethnic polymorphisms of eNOS and CYP2D6 were found in the four Chinese groups. The 4b-G-T wild-type haplotype of eNOS was the most common in Chinese Tibetan (87.1%), Mongolian (79.9%), Uygur (76.4%), and Han (79.5%), respectively. eNOS T-786C creates a new CpG site and a significantly higher methylation level was found in -786CC than that in -786TC in Chinese Han (P = 0.0485) and total Chinese (P = 0.0104). CYP2D6 A-678 (rs28633410) makes the symmetrical CpG site changed to be an asymmetrical CpA site, and the methylation level of cytosine in the CpG context of G-678A was significantly higher than that in the CpA. The results of the present study could be useful for understanding the interindividual disparity of cardiovascular disease susceptibility and drug response among different Chinese ethnic groups and would provide more evidences for the precise medication of Chinese.

Association between PDE4D polymorphism and ischemic stroke in young population

Objective

To explore the association between the polymorphisms of the phosphodiesterase (PDE) 4D gene (SNP83 and SNP87) and the risk of ischemic stroke (IS) in Chinese young population.

Methods

This study included 393 patients who were divided into IS group and non-IS group. Semiconductor high-throughput sequencing technology and multivariate logistic regression analysis were performed.

Results

In the case group, the frequency of CC genotype and C allele of the SNP83 gene was significantly higher than that in the control group. There was no significant difference in genotype frequency distribution of SNP87 between the two groups.

Conclusion

We found an association between SNP83 and the risk of IS in Chinese young population from northern Henan province. There was not a significant association between SNP87 and IS in Chinese young population.

The Role of Polymorphism Gen Methylene Tetra Hydrofolate Reductase (MTHFR) C677T in Ischaemic Stroke Patients with and Without Hypertension

BACKGROUND:

Stroke is a leading cause of disability and remains the second leading cause of death in the world. Some of the pathogenesis of stroke are interactions between genetic and acquired risk factors, the interaction is related with the atherosclerotic which is the main pathogenesis of ischaemic stroke. Previous studies demonstrated an association between methylene tetra hydro folate reductase (MTHFR) genotype and ischaemic stroke; the MTHFR C677T genotype is one of the independent risk factor.

AIM:

This study aims to know about the role of polymorphism gen MTHFR C677T in ischaemic stroke patients with and without hypertension.

METHODS:

This study is a cross-sectional study, the sample was taken consecutively, after approval by the Medical Faculty Science’s Ethics Committee at University Sumatera Utara. All sample matched with inclusion and exclusion criteria, demography data and blood sample were taken. Demography data were analysed using descriptive statistic.

RESULTS:

Of the 106 ischaemic stroke patients were divided into two groups, the first group is patients with hypertension (53 patients), and the second group is without hypertension (53 patients). We have done the PCR- RFLP to all the patients, we got 78 patients with 677CC of MTHFR genotype, 23 patients with 677CT genotype and 5 patients with 677TT genotype. We found polymorphism C677T is more frequent in ischaemic stroke patients with hypertension (16 patients; 69.5%), and all the patient with 677TT genotype are an ischaemic stroke with hypertension (5 patients; 100%).

CONCLUSION:

We concluded that polymorphism MTHFR C677T have an important role in hypertension and ischaemic stroke.

The Methylenetetrahydrofolate Reductase C677T (rs1801133) and Apolipoprotein A5-1131T>C (rs662799) Polymorphisms, and Anemia Are Independent Risk Factors for Ischemic Stroke

BACKGROUND

Although there is adequate knowledge as to the role of traditional cardiovascular risk factors on stroke incidence, knowledge of other risk factors, particularly genetic ones, is still incomplete.

METHODS

To assess the participation of some polymorphisms, along with other modifiable risk factors, a case-control study was conducted. A total of 253 cases were identified in the emergency room of a general regional hospital, with a clinical trait of stroke confirmed by a skull computerized axial tomography scan. In the surgery ward, 253 controls were identified, gender and age (±5 years) matched. Biochemical parameters were measured, and 4 polymorphisms were genotyped by polymerase chain reaction, rs1801133 (methylenetetrahydrofolate reductase [MTHFR]), rs1498373 (dimethylarginine dimethylaminohydrolase type 1 [DDAH1]), rs662799 (apolipoprotein A5 [APOA5]), and rs1799983 (endothelial nitric oxide). Odds ratios were estimated to assess the strength of association, with 95% confidence intervals, both in a matched case-control analysis and in a conditional regression analysis.

RESULTS

Cases had higher mean blood pressure and triglycerides and lower hemoglobin levels. Heterozygous and homozygous subjects to the rs1801133 variant of the MTHFR gene had a 3-fold higher risk of stroke. In the dominant model, those with the polymorphism rs662799 of the promoter region for APOA5 had twice the risk of stroke. Anemia increased the risk of stroke 4-fold.

CONCLUSIONS

Polymorphisms of the genes MTHFR (rs1801133) and APOA5 (rs662799), as well as anemia, are independent risk factors for stroke in Mexicans, together with traditional cardiovascular risk factors such as high triglycerides and high blood pressure.

Relationship of phosphodiesterase 4D (PDE4D) gene polymorphisms with risk of ischemic stroke: a hospital based case-control study

BACKGROUND

Stroke remains a leading cause of death and disability worldwide. Ischemic stroke (IS) accounts for around 80-85% of total stroke and is a complex polygenic multi-factorial disorder which is affected by a complex combination of vascular, environmental, and genetic factors.

OBJECTIVE

The study was conducted with an aim to examine the relationship of single nucleotide polymorphisms (SNPs) of PDE4D (T83C, C87T, and C45T) gene with increasing risk of IS in patients in North Indian population.

METHODS

In this hospital-based case-control study, 250 IS subjects and 250 age-and sex-matched control subjects were enrolled from the Neurosciences Centre, A.I.I.M.S., New Delhi, India. Deoxyribonucleic acids (DNAs) were extracted using the conventional Phenol-Chloroform isolation method. Different genotypes were determined by Polymerase chain reaction- Restriction fragment length polymorphism method. Odds ratio (OR) and 95% Confidence Interval (CI) of relationship of polymorphisms with risk of IS were calculated by conditional multivariable regression analysis.

RESULTS

High blood pressure, low socioeconomic status, dyslipidemia, diabetes, and family history of stroke were observed to be statistically significant risk factors for IS. Multivariable adjusted analysis demonstrated a statistically significant relationship between SNP 83 of PDE4D gene polymorphism and increasing odds of IS under the dominant model of inheritance (OR, 1.59; 95% CI, 1.02 to 2.50; p value = 0.04) after adjustment of potential confounding variables. Stratified analysis on the basis of TOAST classification demonstrated a statistically significant association for increasing 2.73 times odds for developing large vessel disease stroke as compared to controls (OR, 2.73; 95% CI, 1.16 to 0.02; p value = 0.02). We did not find any significant association of SNPs (C87T and C45T) of the PDE4D gene with the risk of IS.

CONCLUSION

SNP 83 of PDE4D gene may increase the risk for developing IS whereas SNP 87 and SNP45 of PDE4D may not be associated with the risk of IS in the North Indian population. Prospective cohort studies are required to corroborate these findings.

A meta-analysis of PDE-gene polymorphism and cerebral infarction risk

Previous studies identified that phosphodiesterase 4D (PDE4D) gene polymorphism might be associated with cerebral infarction or ischemic stroke, and hemorrhagic stroke in human populations. However, as yet, no meta-analysis has revealed any detailed association. We retrospectively reviewed studies regarding the relationship of PDE4D gene polymorphism with ischemic stroke (IS) published during the period January 2003 to September 2012. According to the inclusion criteria, 9 of 105 initial studies were included in the subsequent analysis. The PubMed, Embase and CNKI of China were searched to identify the relevant studies. A total of 186 young patients with IS were included for the meta-analysis and 232 matched control subjects were enrolled and results were presented. The association of PDE4D gene polymorphism with IS in various populations was examined. The results suggested that single nucleotide polymorphism (SNP), SNP 83 in PDE4D gene was significantly related with susceptibility to IS. The meta-analysis also showed that PDE4D gene was associated with an enhanced risk of IS. The meta-analysis suggested that PDE4D SNP 87 constitutes an independent risk factor for IS development. To the best of our knowledge, the present meta-analysis reveals a number of possible associations between PDE4D gene polymorphism and IS.

Transforming growth factor-β1 (C509T, G800A, and T869C) gene polymorphisms and risk of ischemic stroke in North Indian population: A hospital-based case-control study

Background:

Transforming growth factor-beta 1 (TGF-β1) is a multifunctional pleiotropic cytokine involved in inflammation and pathogenesis of cerebrovascular diseases. There is limited information on the association between variations within the TGF-β1 gene polymorphisms and risk of ischemic stroke (IS). The aim of this study was to investigate the association of the TGF-β1 gene (C509T, G800A, and T869C) polymorphisms, and their haplotypes with the risk of IS in North Indian population.

Methods:

A total of 250 IS patients and 250 age- and sex-matched controls were studied. IS was classified using the Trial of Org 10172 in Acute Stroke Treatment classification. Conditional logistic regression analysis was used to calculate the strength of association between TGF-β1 gene polymorphisms and risk of IS. Genotyping was performed using SNaPshot method.

Results:

Hypertension, diabetes, dyslipidemia, alcohol, smoking, family history of stroke, sedentary lifestyle, and low socioeconomic status were found to be associated with the risk of IS. The distribution of C509T, G800A and T869C genotypes was consistent with Hardy-Weinberg Equilibrium in the IS and control groups. Adjusted conditional logistic regression analysis showed a significant association of TGF-β1 C509T (odds ratio [OR], 2.1; 95% CI; 1.2–3.8; P = 0.006), G800A (OR, 4.4; 95% CI; 2.1–9.3; P < 0.001) and T869C (OR, 2.6; 95% CI; 1.5–4.5; P = 0.001) with the risk of IS under dominant model. Haplotype analysis showed that C509-A800-T869 and T509-G800-C869 haplotypes were significantly associated with the increased risk of IS. C509T and T869C were in strong linkage disequilibrium (D' =0.51, r² = 0.23).

Conclusion:

Our results suggest that TGF-β1 polymorphisms and their haplotypes are significantly associated with the risk of IS in North Indian population.

No Association Between Single-Nucleotide Polymorphism 56 (SNP56) in Phosphodiesterase 4D (PDE4D) Gene and Susceptibility to Ischemic Stroke: A Meta-Analysis of 15 Studies

Background

Recent studies demonstrated that polymorphisms in the PDE4D gene were associated with several processes involved in the occurrence of ischemic stroke (IS). The association between specific PDE4D single-nucleotide polymorphism 56 (SNP56) and IS risk was initially identified via genome-wide association studies (GWAS), although the GWAS in different populations produced inconclusive results. Thus, we performed a meta-analysis to better explain the association between PDE4D SNP56 and IS risk.

Material/Methods

A literature search was conducted using PubMed, Embase, and Web of Science up to June 1, 2015. A fixed-effects or random-effects model was used to calculate the pooled odds ratios (ORs) based on the results from the heterogeneity tests.

Results

Finally, we performed a meta-analysis of 15 studies, involving 8731 IS patients and 10,756 controls. The results showed nonsignificant association between PDE4D SNP56 and IS risk (T vs. A: OR=1.01, 95%CI=0.88–1.15, P=0.90). Similarly, in the subgroup analysis by ethnicity, no significant association was observed in Asian (T vs. A: OR=1.08, 95%CI=0.80–1.44, P=0.62) or European (T vs. A: OR=0.96, 95%CI=0.86–1.08, P=0.54) population. Moreover, funnel plots and Egger regression testing showed no evidence of publication bias.

Conclusions

In summary, current evidence suggested that PDE4D SNP56 might not be associated with an increased susceptibility to IS. However, this conclusion needs further validation by well-designed studies with large sample sizes.

Association between Beta-Fibrinogen C148T Gene Polymorphism and Risk of Ischemic Stroke in a North Indian Population: A Case-Control Study

BACKGROUND AND PURPOSE

Stroke is a multifactorial disease influenced by both genetic and environmental factors. The aim of this case-control study was to determine the association between β-fibrinogen C148T (rs1800787) gene polymorphism and susceptibility to ischemic stroke (IS) in a North Indian population.

METHODS

In the present case-control study, genotyping was performed using the PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) method on 250 IS patients and 250 age- and sex-matched controls. Frequency distributions of genotypes and alleles were compared between the cases and controls by conditional logistic regression.

RESULTS

Hypertension, diabetes, dyslipidemia, low socioeconomic status, and family history of stroke were found to be independent risk factors for IS. The mean age of the cases and controls was 52.83 ± 12.59 and 50.97 ± 12.70 years, respectively. Multivariate logistic regression analysis showed an independent association between β-fibrinogen C148T (rs1800787) polymorphism and risk of IS in dominant (OR = 2.19; 95% CI 1.23-3.90; p = 0.007) and allelic (OR = 1.66; 95% CI 1.19-2.33; p = 0.002) models. Based on the Trial of Org 10172 in Acute Stroke Treatment (TOAST) classification, an independent association of small vessel disease with risk of IS was observed in the dominant (OR = 2.09; 95% CI 1.10-3.96; p = 0.02) and allelic (OR = 1.75; 95% CI 1.12-2.75; p = 0.01) models, and a significant association of cardioembolic stroke with risk of IS was seen in the allelic model (OR = 2.11; 95% CI 1.07-4.17; p = 0.02). All the genotype frequencies observed were in accordance with Hardy-Weinberg equilibrium in both cases and controls.

CONCLUSION

The findings of the present study suggest that polymorphism in the C148T position of the β-fibrinogen gene might be a risk factor for IS mainly for the small vessel disease stroke subtype in a North Indian population. Further, large prospective studies are required to confirm these findings.

Association between interleukin-6 (G174C and C572G) promoter gene polymorphisms and risk of ischemic stroke in North Indian population: a case-control study

BACKGROUND

Polymorphisms of G174C and C572G in the interleukin-6 (IL-6) promoter gene can affect both transcription and secretion of IL-6 and may be involved in inflammation related to and pathogenesis of ischemic stroke (IS). Whether these IL-6 gene polymorphisms are risk factors for IS or not, remains controversial.

OBJECTIVE

The aim of this study was to determine the association between IL-6 G174C and C572G gene polymorphisms and susceptibility to ischemic stroke in North Indian Population.

METHODS

Two hundred and fifty IS patients and 250 age- and sex-matched controls were studied. Genotyping was performed using SNaPshot method. Stroke was classified using Trial of Org 10172 in acute stroke treatment classification. Conditional logistic regression analysis was used to calculate the strength of association between IL-6 (G174C and C572G) polymorphisms and risk of IS.

RESULTS

Hypertension, diabetes, dyslipidemia, alcohol, smoking, family history of stroke, sedentary life style and low socioeconomic status were found to be associated with the risk of IS. Conditional logistic regression analysis showed a significant association of IL-6 G174C with the risk of IS under dominant model (OR, 1.61; 95%CI, 1.0-2.4; P value 0.02) and allelic model (OR, 1.5; 95%CI, 1.0-2.1; P value 0.02). For IL-6 C572G, multivariate adjusted analysis showed a significant association with the risk of IS under dominant model for overall IS (OR, 1.81; 95%CI, 1.04-3.15; P value 0.03) and small vessel disease subtype of IS (OR, 2.8; 95%CI, 1.3-6.0; P value 0.006).

CONCLUSION

Our results suggest that IL-6 (G174C) polymorphism is significantly associated with the risk of IS in North Indian population. However, IL-6 (C572G) polymorphism is found significantly associated with the risk of IS after adjusting the demographic and risk factors variables. Prospective studies with large sample size are required for independent validation. Our findings could be helpful in identifying individuals at increased risk for developing IS.

Phosphodiesterase 4D gene polymorphisms in sudden sensorineural hearing loss

The phosphodiesterase 4D (PDE4D) gene has been reported as a risk gene for ischemic stroke. The vascular factors are between the hypothesized etiologies of sudden sensorineural hearing loss (SSNHL), and this genetic effect might be attributed for its role in SSNHL. We hypothesized that genetic variants of the PDE4D gene are associated with susceptibility to SSNHL. We conducted a case-control study with 362 SSNHL cases and 209 controls. Three single nucleotide polymorphisms (SNPs) were selected. The genotypes were determined using TaqMan technology. Hardy-Weinberg equilibrium (HWE) was tested for each SNP, and genetic effects were evaluated according to three inheritance modes. We carried out sex-specific analysis to analyze the overall data. All three SNPs were in HWE. When subjects were stratified by sex, the genetic effect was only evident in females but not in males. The TT genotype of rs702553 exhibited an adjusted odds ratio (OR) of 3.83 (95 % confidence interval = 1.46-11.18) (p = 0.006) in female SSNHL. The TT genotype of SNP rs702553 was associated with female SSNHL under the recessive model (p = 0.004, OR 3.70). In multivariate logistic regression analysis, TT genotype of rs702553 was significantly associated with female SSNHL (p = 0.0043, OR 3.70). These results suggest that PDE4D gene polymorphisms influence the susceptibility for the development of SSNHL in the southern Taiwanese female population.

Low socioeconomic status is an independent risk factor for ischemic stroke: a case-control study in North Indian population

BACKGROUND

Stroke is a multifactorial disease and is influenced by complex environmental interactions. The contribution of various risk factors to the burden of stroke worldwide is not well known, particularly in developing countries. The present case-control study is aimed at exploring the association between a low socioeconomic status and the risk of ischemic stroke among the North Indian population.

METHODS

The study design was a hospital-based, case-control study. Age- and sex-matched controls were included. The demographic characteristics and risk factor variables were documented by means of a personal interview through a standardized case record form. The household asset index for determining the socioeconomic status (HAISS) was used for the assessment of the socioeconomic status of the population. HAISS was validated with the widely used Kuppuswamy scale for measurement of socioeconomic status. The multivariable logistic regression model was used to estimate the odds ratio associated with stroke.

RESULTS

In all, 224 ischemic stroke patients and 224 controls were recruited between February 2009 and February 2012. The mean age of cases and controls was 53.47 ± 14 and 52.92 ± 13.4, respectively. The low economic status was independently associated with the risk of ischemic stroke after adjustment for demographic and risk factor variables (OR 2.8; 95% CI 1.2-6.3).

CONCLUSION

Our findings suggest that there is a significant association between a low socioeconomic status and the risk of ischemic stroke risk in North Indian population. Well-designed studies embedded with long-term prospective cohorts are required for confirming the results.

Association between angiotensin converting enzyme gene insertion/deletion polymorphism and intracerebral haemorrhage in North Indian population: a case control study and meta-analysis

The purpose of this study was to determine the relationship between Angiotensin converting enzyme (ACE) insertion/deletion polymorphism and ICH with an ACE level in a North Indian population. Patient with ICH and age- and sex- matched control subjects were recruited. Case control study design was used. Genotyping was performed by using Polymerase chain reaction. Serum ACE levels were measured by colorimetric method. Our results were integrated with other reported studies across different countries in a meta-analysis. One hundred and six patients with ICH and 106 age- and sex- matched control subjects were recruited. Mean age of cases and control subjects were 53.4 ± 1 and 52.9 ± 13.4, respectively. The DD genotypes were more frequency distributed in cases compared with controls (OR 2; 95 % CI, 1.02-3.8, P = 0.04) under a recessive model of inheritance. Meta-analysis suggests significant association between ACE I/D polymorphism and risk of ICH (OR 1.98; 95 % CI, 1.53-2.57) under the recessive model of inheritance and under the dominant model of inheritance (OR 1.31; 95 % CI, 1.18-1.45). The findings of the present study show a significant association between ACE insertion/deletion polymorphism and ICH. Meta-analysis indicate that ACE I/D polymorphism may be a susceptible marker for risk factor of ICH in Asian population.

Relationship between polymorphisms in beta -2 adrenergic receptor gene and ischemic stroke in North Indian Population: a hospital based case control study

Background

Stroke is a multi-factorial disease and influenced by both genetic and environmental factors. The purpose of the present case control study was to check the relationship between beta-2 adrenergic receptor (ADRB2) polymorphism and ischemic stroke in North Indian Population.

Methods

In a hospital based case control study, patients with ischemic stroke and control subjects from outpatient department and neurology ward of All India Institute of Medical Sciences New Delhi. Genotyping was performed by using Polymerase chain reaction–Restriction fragment length polymorphism. Frequency distributions of genotypes and alleles were compared between cases and controls using multivariate logistic regression.

Results

In this study, 224 patients and 224 age-and sex-matched control subjects were recruited. Mean age of cases and controls were 53.9 ± 13.4 and 53.6 ± 12.9 years respectively. Multivariate logistic regression analysis showed an independent association between Gln27Glu polymorphism and large vessel stroke (LVD) under a recessive model of inheritance (OR 3.9; 95% CI 1.3 to 11). An age-stratified analysis, suggested independent association between Gln27Glu polymorphism and ischemic stroke, large vessel disease and small vessel disease stroke who had onset of disease at an older age.

Conclusions

The findings of the present study suggest that Gln27Glu polymorphism of the ADRB2 gene may confer higher risk of large vessel disease stroke in a North Indian population. Prospective studies with larger sample size are required for independent validation.