Mutations and polymorphisms in genes affecting hemostasis proteins and homocysteine metabolism in children with arterial ischemic stroke

Serum Fibrinogen and Renal Dysfunction as Important Predictors of Left Atrial Thrombosis in Patients with Atrial Fibrillation

BACKGROUND

As has been shown previously, patients with atrial fibrillation (AF) who have left atrial thrombus (LAT) also have elevated plasma concentrations of fibrinogen. In this study, we tried to determine if this is the consequence of a genetic trait and whether elevated concentrations of fibrinogen could be used to predict LAT in patients with AF.

METHODS

We recruited 181 consecutive patients scheduled for pulmonary vein isolation (PVI) or direct current cardioversion. The primary endpoint was the presence of LAT on transesophageal echocardiography (TOE). We recorded routine clinical and biochemical data as well as the polymorphism type of the fibrinogen gene for the β chain. To control potentially interfering variables, we performed propensity score matching (PSM). Multivariable and univariable logistic regression models (LRM) were computed using the CHA2DS2-Vasc score, the fibrinogen concentration and creatinine clearance as estimated by the Cockcroft-Gault equation.

RESULTS

60 of 181 patients had LAT as detected by TOE. As expected, patients with LAT had significantly higher concentrations of fibrinogen (3.9 vs. 3.6 g/L); p = 0.01 in the unadjusted analysis. After performing PSM, there were no statistically significant differences between the groups, except for creatinine clearance (79.9 vs. 96.8 mL/min); p = 0.01. There were also no differences regarding the -455 G/A βfibrinogen polymorphism distribution between the two groups. After constructing the LRM, we found no performance enhancement for the CHA2DS2-Vasc score by adding the fibrinogen concentration or creatinine clearance alone, but when all three variables were put together, there was a significant improvement in LAT prediction (AUC 0.64 vs. 0.72), p = 0.026.

CONCLUSION

Our study found no evidence of elevated levels of circulating fibrinogen in patients with LAT or a connection between those levels and the A/A and A positive polymorphism. When used together with renal function markers such as creatinine clearance, plasma fibrinogen concentrations can provide additional power to the CHA2DS2-Vasc score for predicting LAT.

Parkinson's Disease Risk and Hyperhomocysteinemia: The Possible Link

Parkinson's disease (PD) is one of the most common degenerative brain disorders caused by the loss of dopaminergic neurons in the substantia nigra (SN). Lewy bodies and -synuclein accumulation in the SN are hallmarks of the neuropathology of PD. Due to lifestyle changes and prolonged L-dopa administration, patients with PD frequently have vitamin deficiencies, especially folate, vitamin B6, and vitamin B12. These disorders augment circulating levels of Homocysteine with the development of hyperhomocysteinemia, which may contribute to the pathogenesis of PD. Therefore, this review aimed to ascertain if hyperhomocysteinemia may play a part in oxidative and inflammatory signaling pathways that contribute to PD development. Hyperhomocysteinemia is implicated in the pathogenesis of neurodegenerative disorders, including PD. Hyperhomocysteinemia triggers the development and progression of PD by different mechanisms, including oxidative stress, mitochondrial dysfunction, apoptosis, and endothelial dysfunction. Particularly, the progression of PD is linked with high inflammatory changes and systemic inflammatory disorders. Hyperhomocysteinemia induces immune activation and oxidative stress. In turn, activated immune response promotes the development and progression of hyperhomocysteinemia. Therefore, hyperhomocysteinemia-induced immunoinflammatory disorders and abnormal immune response may aggravate abnormal immunoinflammatory in PD, leading to more progression of PD severity. Also, inflammatory signaling pathways like nuclear factor kappa B (NF-κB) and nod-like receptor pyrin 3 (NLRP3) inflammasome and other signaling pathways are intricate in the pathogenesis of PD. In conclusion, hyperhomocysteinemia is involved in the development and progression of PD neuropathology either directly via induction degeneration of dopaminergic neurons or indirectly via activation of inflammatory signaling pathways.

Association of methylenetetrahydrofolate reductase (MTHFR) rs1801133 (677C>T) gene polymorphism with ischemic stroke risk in different populations: An updated meta-analysis

Background: Recently, increasing evidence has implicated methylenetetrahydrofolate reductase (MTHFR) gene mutation as a risk factor for ischemic stroke (IS) in the general population. However, studies have been inconclusive and lack evidence on specific populations. We aim to determine whether the rs1801133 (NC_000001.11 (MTHFR):g. 677C>T (p.Ala222Val) variant, we termed as MTHFR rs1801133 (677 C>T), is linked to an increased risk of IS in different age groups and ancestry groups. Methods: The literature relevant to our study was found by searching the PubMed, Cochrane Library, Web of Science, EMBASE, and CNKI databases. A random effect model analysis was used to calculate the pooled odds ratio (OR) and 95% confidence interval (CI) to evaluate any possible association. We conducted a subgroup analysis based on the age and ancestry groups of the included populations. Results: As of March 2022, 1,925 citations had been identified in electronic databases, of which 96 studies involving 34,814 subjects met our eligibility criteria. A strong link was found between IS and the MTHFR gene rs1801133 (677C>T) polymorphism in all genetic models [dominant genetic model (OR = 1.47; 95%CI = 1.33-1.61; p < 0.001), recessive genetic model (OR = 1.52; 95%CI = 1.36-1.71; p < 0.001), heterozygous model (OR = 1.36; 95%CI = 1.24-1.48; p < 0.001), homozygous model (OR = 1.82; 95%CI = 1.58-2.11; p < 0.001), and T allelic genetic model (OR = 1.37; 95%CI = 1.27-1.48; p < 0.001)]. Further subgroup analyses indicated that the MTHFR rs1801133 (677C>T) variant may increase the risk of IS in Asian, Hispanic, or Latin population, middle-aged, and elderly populations (p < 0.001). Conclusion: Our results implied that mutation of the T allele of MTHFR rs1801133 (677C>T) could be a risk factor for IS. A significant association was found among Asian, Hispanic, or Latin population, middle-aged, and elderly people.

The Genetic Basis of Strokes in Pediatric Populations and Insight into New Therapeutic Options

Strokes within pediatric populations are considered to be the 10th leading cause of death in the United States of America, with over half of such events occurring in children younger than one year of life. The multifactorial etiopathology that has an influence on stroke development and occurrence signify the importance of the timely recognition of both modifiable and non-modifiable factors for adequate diagnostic and treatment approaches. The early recognition of a stroke and stroke risk in children has the potential to advance the application of neuroprotective, thrombolytic, and antithrombotic interventions and rehabilitation strategies to the earliest possible timepoints after the onset of a stroke, improving the outcomes and quality of life for affected children and their families. The recent development of molecular genetic methods has greatly facilitated the analysis and diagnosis of single-gene disorders. In this review, the most significant single gene disorders associated with pediatric stroke are presented, along with specific therapeutic options whenever they exist. Besides monogenic disorders that may present with stroke as a first symptom, genetic polymorphisms may contribute to the risk of pediatric and perinatal stroke. The most frequently studied genetic risk factors are several common polymorphisms in genes associated with thrombophilia; these genes code for proteins that are part of the coagulation cascade, fibrolysis, homocystein metabolism, lipid metabolism, or platelets. Single polymorphism frequencies may not be sufficient to completely explain the stroke causality and an analysis of several genotype combinations is a more promising approach. The recent steps forward in our understanding of the disorders underlying strokes has given us a next generation of therapeutics and therapeutic targets by which to improve stroke survival, protect or rebuild neuronal connections in the brain, and enhance neural function. Advances in DNA sequencing and the development of new tools to correct human gene mutations have brought genetic analysis and gene therapy into the focus of investigations for new therapeutic options for stroke patients.

MTHFR A1298C gene polymorphism on stroke risk: an updated meta-analysis

Background

Previous studies have shown the effect of MTHFR A1298C gene polymorphism on stroke risk. But the results of published studies remained inconclusive and controversial. So we conducted a meta-analysis to accurately estimate the potential association between MTHFR A1298C gene polymorphism and stroke susceptibility.

Methods

A systematic literature search on Embase, Pubmed, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI) and WanFang electronic database identified 40 articles including 5725 cases and 8655 controls. Strength of association was evaluated by pooled odds ratio (OR), 95% confidence interval (CI) and p value. Funnel plots and Begger’s regression test were applied for testing the publication bias. Statistical analysis of all data was performed by Stata 12.0.

Results

The meta-analysis results indicated a significant relationship between MTHFR gene A1298C polymorphisms and stoke risk under the C allelic genetic model (OR = 1.19, 95%CI = 1.07–1.32, p = 0.001), dominant genetic model (OR = 1.19, 95%CI = 1.06–1.33, p = 0.004) and recessive genetic model (OR = 1.43, 95%CI =1.15–1.77, p = 0.001). In subgroup analysis, we discovered obvious correlation in three genetic model of Asian, stroke type, adult by ethnicity, population, stroke type, source of control and case size. Additionally, in studies of control from hospital and case size equal 100, obvious correlation was also found in the three genetic model.

Conclusions

Our meta-analysis results indicated that there was evidence to support the correlation between MTHFR A1298C polymorphism and stroke susceptibility, especially in adults and ischemic stroke.

Association of SERPINE1 rs1799889 polymorphism with arterial ischemic stroke in children: a systematic review and meta-analysis

Inherited thrombophilias are well-established predisposing factors for venous thromboembolism, but their role in arterial ischemic stroke (AIS) in children, remains unclear. The association between SERPINE1 rs1799889 polymorphism and AIS in children was evaluated by several studies, whereas the results were conflicting. Thus, we performed this meta-analysis to combine and analyze the available studies in order to provide a more accurate result on the association. PubMed, Scopus, EMBASE, SciELO, MedRxiv, China Biology Medicine Disk, DeepDyve, CNKI, and Web of Science were used to identify all relevant articles published up to 30 November 2020, without any restrictions on ethnicity. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the associations. A total of eight case-control studies with 600 cases and 2,156 controls were selected. No significant association between SERPINE1 rs1799889 polymorphism and AIS in children susceptibility was noted. In the stratified analyses by ethnicity, source of controls, genotyping methods, and age groups, there was still no significant association between SERPINE1 rs1799889 polymorphism and AIS risk in children. This study suggested that SERPINE1 rs1799889 polymorphism might be not related to etiology of AIS in children. Moreover, well-designed, large-scale and multicenter clinical studies are required to improve and validate these results.Supplemental data for this article is available online at https://doi.org/10.1080/15257770.2021.1966798 .

Association of PAI-1 rs1799889 Polymorphism with Susceptibility to Ischemic Stroke: a Huge Meta-Analysis based on 44 Studies

BACKGROUND

the PAI-1 rs1799889 polymorphism has been reported to be associated with susceptibility to ischemic stroke. However, the results of previous studies have been inconsistent or controversial. Hence, we performed a systematic review and meta-analysis to evaluate the association of PAI-1 rs1799889 polymorphism with ischemic stroke risk.

METHODS

A comprehensive literature search was performed on PubMed, Web of Science, Scopus, SciELO, CNKI, and CBD databases up to November 05, 2019. Pooled odds ratio (OR) with 95% confidence interval (CI) were used to access the strength of this association in fixed- or random-effects model.

RESULTS

A total of 44 case-control studies with 8,620 cases and 10,260 controls were selected. Pooled data showed a significant association between PAI-1 rs1799889 polymorphism and ischemic stroke risk in the overall populations (GG vs. AA: OR = 0.791, 95% CI 0.633-0.988, p = 0.039; GA vs. AA: OR = 0.807, 95% CI 0.683-0.953, p = 0.012; and GG+GA vs. AA: OR = 0.795, 95% CI 0.637-0.993, p = 0.043). Subgroup analysis by ethnicity revealed a significant association in Asian and Mixed populations, but not in Caucasians. Moreover, stratified analysis by country of origin revealed an increased risk of ischemic stroke in Chinese populations, but not among Dutch (Netherlands) and Swedish.

CONCLUSIONS

This meta-analysis result suggested that PAI-1 rs1799889 polymorphism was associated with an increased risk of ischemic stroke, especially in Asian and Mixed populations.

Relationship between methylenetetrahydrofolate reductase (MTHFR) gene (A1298C) polymorphism with the risk of stroke: A systematic review and meta-analysis

Studies on relationship between methylenetetrahydrofolate reductase gene (MTHFR) gene A1298C polymorphism with the risk of ischemic as well as hemorrhagic stroke have shown discordant results. Present meta-analysis was aimed to clarify the relationship between MTHFR gene A1298C polymorphism with risk of stroke. A comprehensive literature search for all published articles was performed in electronic database including PubMed, EMbase, Cochrane Library, Trip Databases, Worldwide Science, CINAHL, and Google Scholar up to 31st  December 2019. Pooled odds ratio (ORs) with 95% confidence interval (CIs) under dominant, recessive, and allelic models was calculated. Sensitivity analysis was also performed to detect the heterogeneity. In our meta-analysis, a total of 20 studies with 19 case control studies involving 2871 ischemic stroke (IS) cases and 3984 controls and 3 studies with 201 hemorrhagic stroke cases and 1349 controls were included. Our findings suggest that there was a significant relationship between MTHFR gene A1298C gene polymorphism with risk of ischemic stroke (dominant model: OR = 1.32, 95% CI = 1.06-1.66, recessive model: OR = 1.45, 95% CI = 1.06-1.99 and allelic model: OR = 1.35, 95% CI = 1.00-1.84, respectively). However, no significant relationship between MTHFR gene A1298C gene polymorphism with the risk of hemorrhagic stroke. Findings of this meta-analysis concludes that MTHFR gene A1298 C polymorphism could be capable of increasing stroke susceptibility in Asian, but not in Caucasian population. Genotyping of MTHFR gene A1298C polymorphism may be used as a predictor for the occurrence of ischemic stroke.

Lack of Associations Between PAI-1 and FXIII Polymorphisms and Arterial Ischemic Stroke in Children: A Systematic Review and Meta-Analysis

The role of genetic risk factors for ischemic stroke seems to be in particular significance in pediatric patients. Numerous polymorphic variants of genes encoding proteins, that is, plasminogen activator inhibitor as well as coagulation factors, involved in the coagulation cascade may be related to arterial ischemic stroke (AIS) both in adults and children. We performed systematic review and 2 meta-analyses to assess possible correlations between common plasminogen activator inhibitor (PAI-1) and FXIII polymorphisms and ischemic stroke in children. We searched PubMed to identify available data published before October 2018 using appropriate keywords and inclusion criteria. Finally, 12 case-control studies were included: 8 analyzing PAI-1 polymorphism (600 children with stroke and 2152 controls) and 4-FXIII polymorphism (358 children with stroke and 451 controls). R and Comprehensive Meta-Analysis software were used to analyze the impact of the particular polymorphism in the following models: dominant, recessive, additive, and allelic. No publication bias was observed in both meta-analyses. In case of PAI-1 polymorphism, we observed no relation between 4G4G genotype of 4G allele and ischemic stroke in children. We also demonstrated lack of association between FXIII polymorphism and childhood ischemic stroke. In children with AIS, the PAI-1 and FXIII polymorphisms are not risk factors for the disease.

Is the 1298A>C polymorphism in the MTHFR gene a risk factor for arterial ischaemic stroke in children? The results of meta-analysis

An elevated level of homocysteine is a risk factor for vascular diseases, brain atrophy and several other disorders. The 1298A>C polymorphism (rs1801131) leads to mildly decreased MTHFR activity. Previously, it was observed that the MTHFR 1298A>C polymorphism in combined analysis with the MTHFR 677C>T polymorphism increases homocysteine levels. However, conflicting results on its relation to ischaemic stroke in children can be found. We conducted a meta-analysis to analyse possible connections between the MTHFR 1298A>C polymorphism and ischaemic stroke in paediatric patients. We identified available data published before December 2016 using appropriate keywords and searching PubMed as well as the references cited in the found articles. Eight case-control studies were included in the meta-analysis (426 children with stroke and 778 controls). Statistical analyses were made using R and Comprehensive Meta-Analysis softwares to investigate the impact of polymorphism in four models: dominant, recessive, additive and allelic. No publication bias was observed in the meta-analysis. We demonstrated no relationship between the 1298A>C polymorphism and ischaemic stroke in children in the case of recessive, additive and allelic models. However, the results of the dominant model analysis should be treated with caution due to the sensitivity analysis results. After omitting one of the included study, we observed a significant association between the carriers of the MTHFR C allele (cases with AC + CC genotypes) and ischaemic stroke in children (OR 1.35 95% CI 1.02-1.79, p = 0.035 in a fixed effects model). In conclusion, the 1298A>C polymorphism in the MTHFR gene is not a risk factor for ischaemic stroke in paediatric patients.

The β-fibrinogen gene 455G/A polymorphism associated with cardioembolic stroke in atrial fibrillation with low CHA2DS2-VaSc score

Previous work has suggested that ischemic stroke (IS) may be more likely to occur in individuals with a genetic predisposition. In this study, we investigated the potential association of IS-relevant genetic risk factors with cardioembolic stroke (CES) in atrial fibrillation (AF) patients with low CHA2DS2-VaSc score. Genotyping was performed using the GenomeLab SNPstream genotyping platform for five IS-relevant SNPs (MMP-9 C1562T, ALOX5AP SG13S114A/T, MTHFR 677 C/T, FGB 455 G/A, and eNOS G298A) in 479 AF patients with CES and 580 age and sex-matched AF patients without CES. The multivariate analysis adjusted for potential confounders and demonstrated that FGB 455 G/A was independently associated with increased risk of CES in AF patients and the significance remained after Bonferroni correction in the additive, dominant, and recessive models with ORs of 1.548 (95% CI: 1.251–1.915, P = 0.001), 1.588 (95% CI: (1.226–2.057, P = 0.003), and 2.394 (95% CI: 1.357–4.223, P = 0.015), respectively. Plasma fibrinogen levels were significantly higher in patients with the A allele compared with patients with genotype of GG (3.29 ± 0.38 mg/dl vs. 2.87 ± 0.18 mg/dl, P < 0.001). We found for the first time that the A allele of FGB 455 G/A was a risk factor for CES in AF patients, probably by elevating the level of plasma fibrinogen.

Association Between the 20210G>A Prothrombin Gene Polymorphism and Arterial Ischemic Stroke in Children and Young Adults-Two Meta-analyses of 3586 Cases and 6440 Control Subjects in Total

BACKGROUND

Previous data have shown that the 20210G>A polymorphism of the Factor II gene is related to an increased prothrombin level, which may in turn lead to a procoagulant state. The heterogeneous and multifactorial character of arterial ischemic stroke often results in contradictory reports describing the association between the 20210G>A polymorphism and arterial ischemic stroke in different populations. We performed a meta-analysis of available data addressing the relation between the FII 20210G>A polymorphism and arterial ischemic stroke, both in young adults and children.

METHODS

We searched PubMed using appropriate keywords. The inclusion criteria for the study were as follows: case-control study, study population consisting of children, study population consisting of young adults, arterial ischemic stroke confirmed by magnetic resonance imaging or computed tomography, and English language. The exclusion criteria included lack of genotype or allele frequencies, study design other than a case-control study, outcome definition other than arterial ischemic stroke, and previously overlapped patient groups. Finally, 30 case-control studies (14 in children and 16 in young adults) were included. Statistical analyses were conducted using R software. Heterogeneity between the studies was evaluated using the Dersimonian and Laird's Q test. In the case of significant between-studies heterogeneity, the pooled odds ratio was estimated with a random-effects model, otherwise a fixed-effects model was used.

RESULTS

The pooled analysis showed that carriers of 20210A allele (GA+AA genotypes) of the prothrombin gene are more common in arterial ischemic stroke patients, both in children and young adults, than in control subjects (P = 0.006; odds ratio, 1.83; 95% confidence interval, 1.19 to 2.80 and P = 0.001; odds ratio, 1.69; 95% confidence interval, 1.25 to 2.28, respectively).

CONCLUSIONS

The results of the present meta-analysis have proven that the FII 20210G>A polymorphism is associated with arterial ischemic stroke in both pediatric and young adult patients.

Association of Polymorphisms in Coagulation Factor Genes and Enzymes of Homocysteine Metabolism With Arterial Ischemic Stroke in Children

Despite the identification of a wide range of inherited and acquired risk factors for arterial ischemic stroke (AIS) in children, genetic risk factors are incompletely characterized and may vary among different populations. We investigated the role of individual and combined inherited prothrombotic and intermediate-risk factors in 73 children with perinatal (n = 35) and childhood AIS (n = 38) and 100 age- and sex-matched controls. Ten polymorphisms in 8 candidate genes encoding coagulation and fibrinolytic proteins (factor V [FV] Leiden, FV HR2, factor II [FII] G20210A, β-fibrinogen [β-FBG]-455G>A, factor XIII [FXIII]-A p.Val34Leu, plasminogen activator inhibitor 1 4G/5G), homocysteine metabolism (methylenetetrahydrofolate reductase [MTHFR] C677T, MTHFR A1298C), and intermediate-risk factors (angiotensin-converting enzyme I/D, apoE ∊2-4) were detected using a multilocus genotyping assay. Allele-specific polymerase chain reaction was used for the determination of human platelet alloantigens (HPA-1, HPA-2, HPA-3, and HPA-5). Factor V Leiden was associated with an increased risk of AIS (odds ratio [OR]: 4.72, 95% confidence interval [CI]: 1.22-18.27) and perinatal AIS (OR: 8.29, 95% CI: 1.95-35.24). Human platelet antigen-3b allele carriers had a 2-fold lower risk of AIS (OR: 0.51, 95% CI: 0.26-0.98) and perinatal AIS (OR: 0.40, 95% CI: 0.18-0.92). A 2.21-fold increased risk of childhood AIS (95% CI: 1.03-4.73) was identified in FXIII-A Leu34 allele carriers. Combined FV Leiden/FV HR2, FV Leiden/MTHFR A1298C, FV Leiden/MTHFR C677T/MTHFR A1298C, and FV Leiden/FV HR2/MTHFR A1298C heterozygosity was identified in children with AIS but not in controls, which revealed a statistically significant difference. This case-control study shows that besides already documented association between FV Leiden and AIS, other previously unreported polymorphisms (FXIII-A p.Val34Leu, HPA-3) and several genotype combinations that always include heterozygous FV Leiden can be related to AIS in Croatian population.

Association Between Plasminogen Activator Inhibitor-1 Genetic Polymorphisms and Stroke Susceptibility

The plasminogen activator inhibitor-1 (PAI-1) is a candidate gene for stroke based on PAI-1's crucial role in fibrinolytic system. However, association studies have yielded conflicting results regarding the association between PAI-1 polymorphisms and stroke susceptibility. To further elucidate the putative association, we performed a systematic review and meta-analysis to provide a complete picture of the loci investigated for association of PAI-1 polymorphism with stroke risk and to derive a precise estimation. PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched until June 2015 to identify eligible studies. Forty data sets from 39 studies with a total of 8336 cases and 14,403 controls were included. The most commonly investigated polymorphism was -675 4G/5G, followed by -844 G/A, 11053 T>G, HindIII C/G, and (CA)n. Overall, our meta-analysis provided evidence for the significant association of PAI-1 4G/5G polymorphism with an increased risk of adult but not pediatric ischemic stroke (adult: 4G/4G vs. 4G/5G + 5G/5G, OR = 1.21, 95 % CI = 1.04-1.42). In the subgroup analysis, significant association was detected in Asians (4G/4G vs. 4G/5G + 5G/5G, OR = 1.45, 95 % CI = 1.14-1.85) but not Caucasians. Moreover, we found that -844 G/A but not 11053 T>G polymorphism was associated with an increased risk of ischemic stroke (-844G/A: A/A vs. G/G: OR = 1.32, 95 % CI = 1.01-1.73). A tendency of PAI-1 4G/5G polymorphism towards a decreased risk of hemorrhagic stroke was observed (4G/4G + 4G/5G vs. 5G/5G, OR = 0.77, 95 % CI = 0.59-1.02, P = 0.066). Future well-designed studies in large well-characterized sample size and presenting results stratified by gender, age, and stroke subtype are warranted.

Fibrinogen alpha and beta gene polymorphisms in pediatric stroke--case-control and family based study

BACKGROUND/PURPOSE

Data on the role of the -455G > A polymorphism of the gene encoding β fibrinogen subunit (FGB) and the Thr312Ala polymorphism of the gene for the α fibrinogen subunit (FGA) in childhood ischemic stroke are insufficient. Therefore the aim of the study was to evaluate a possible association between these two polymorphisms and arterial ischemic stroke.

METHODS

The study group consisted of 85 children after ischemic stroke, 146 of their parents and 159 controls. Both polymorphisms were genotyped using the restriction fragment length polymorphism method. Two study designs were used: a case-control model and a family-based transmission-disequilibrium test. Statistica 7.1 and EpiInfo 6 softwares were used in all analyses.

RESULTS

In the TDT test, a tendency to a higher transmission of the 312Ala allele of the FGA gene and the -455A allele of the FGB gene was observed, however, it was statistically non-significant. The frequencies of alleles and genotypes of both FGA and FGB genes polymorphisms did not differentiate children from both groups also in the case-control model. Additive or synergistic effects between FGA and FGB genes polymorphisms were not observed.

CONCLUSION

An analysis of the results obtained in this study and a critical review of previously published data indicate that examined gene polymorphisms are not related to ischemic stroke in children.

The role of biochemical risk factors in the etiology of AIS in children and adults

Stroke is an abrupt onset of both focal and global neurological deficits secondary to a vascular event lasting more than 24 h and with a vascular background as its only cause. It can be triggered by a rupture of a blood vessel, aneurysm (hemorrhagic stroke, HS), thrombosis or embolisms (ischemic stroke, IS). In developed countries, it is the third most common cause of death in the adult population. Stroke in children is a rare disorder with a reported frequency of about 3 cases per 100,000 children per year. The history of acute brain ischemia is burdened with neurological complications such as motor impairment, speech impairment and intellectual delay. Moreover, in children after AIS seizures and epilepsy are also quite common. Stroke is a heterogeneous disorder; its risk factors in adults are well known, however, in pediatrics, in more than 20% cases, the cause of stroke is impossible to determine. Due to the fact that stroke usually arises as a consequence of the cerebral thrombosis, many of the mechanisms responsible for its occurrence can be considered as risk factors. We have reviewed the recent case-control studies conducted on pediatric patients regarding biochemical risk factors such as elevated levels of homocysteine, fibrinogen, protein C, protein S, antithrombin III, lipoprotein(a), cholesterol and its fractions, and compared them with the results obtained from adult patients.

A polymorphism (-455G>A) in the β-fibrinogen gene is associated with an increased risk of cerebral infarction in the Chinese population: A meta-analysis

BACKGROUND

Previous studies have investigated the association between a polymorphism (-455 G>A) in the β-fibrinogen gene and the risk of cerebral infarction. However, these results are controversial. To shed light on these inconclusive findings, we performed a meta-analysis of studies relating the β-fibrinogen genetic polymorphism (-455 G>A) to the risk of cerebral infarction.

METHODS

We identified literature published before July 2013 by searching PubMed, EMBASE, ISI Web of Science, the Chinese National Knowledge Infrastructure database (CNKI) and the Wanfang database in China and by reviewing the references of retrieved articles. We included studies that reported odds ratio (OR) with 95% confidence interval (CI) for the association between the β-fibrinogen genetic polymorphism and cerebral infarction risk. Publication bias was tested by a funnel plot, and the OR of all studies were combined dependent on the results of the heterogeneity tests among the individual studies. The software Review Manager (Version 5.2) was used for meta-analysis.

RESULTS

Twenty independent case-control studies containing 9477 subjects were included. Our results showed that the -455 G>A polymorphism in the β-fibrinogen gene was associated with the increased risk of cerebral infarction [(AA+GA) vs. GG, OR=1.17, 95%CI: 1.04-1.31, p=0.008; A vs. G, OR=1.12, 95%CI: 1.01-1.23, p=0.03] in the Chinese population by a meta-analysis. However, we did not find this association in the Caucasian population [(AA+GA) vs. GG, OR=0.99, 95%CI: 0.87-1.11, p=0.84; A vs. G, OR=0.97, 95%CI: 0.84-1.13, p=0.73, respectively].

CONCLUSION

The results of our meta-analysis indicate that the -455 G>A polymorphism in the β-fibrinogen gene is a susceptibility marker of ischemic cerebral infarction in the Chinese population.

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.

Global fibrinolytic activity, PAI-1 level, and 4G/5G polymorphism in Thai children with arterial ischemic stroke

BACKGROUND

Prolonged euglobulin clot lysis time (ECLT) and increased level of plasminogen activator inhibitor-1 (PAI-1) were reported to be risk factors of arterial ischemic stroke (AIS) by some studies; however, these findings were not supported by other studies. The objective of this study was to determine the association of ECLT, PAI-1 level, and polymorphisms of 4G and 5G of PAI-1 gene to the development of AIS in Thai children.

METHODS

This study included patients aged 1-18 years old. Diagnosis of AIS was confirmed by imaging study. The control group was age- and sex-matched healthy subjects. Demographic data were recorded, and blood was tested for ECLT, PAI-1 level, lipid profiles, fasting blood sugar (FBS), and 4G and 5G polymorphisms of PAI-1 gene.

RESULTS

There were 70 subjects participating in this study, consisting of 30 patients and 40 controls. Demographic data, lipid profiles, and FBS were similar between the 2 groups. Furthermore, ECLT and PAI-1 level did not differ between patient and control groups; however, both showed significant correlation (r = .352, P = .006). The 4G/5G polymorphism was the most common genotype in both patient and control groups (69.0% vs. 80.0%). However, 4G and 5G polymorphisms of PAI-1 gene did not correlate with PAI-1 level in this study (P = .797).

CONCLUSIONS

The PAI-1 level and 4G/5G polymorphism may not be a risk factor of AIS in this population. It was also found that the 4G/5G polymorphism was the most common PAI-1 genotype in this study.

Quantitative assessment of association between rs1801133 polymorphism and susceptibility to stroke

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to stroke. To assess the association between this polymorphism and stroke risk, we conducted a comprehensive meta-analysis based on 73 eligible studies. A total of 73 studies, including 10,225 cases and 13,800 controls identified between 1999 and 2012, were selected through researching the PubMed, MEDLINE, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Chinese National Knowledge Infrastructure and Literature database databases. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of stroke risk was associated with the rs1801133 polymorphism in all genetic models (homozygote model: OR 1.296, 95% CI 1.109-1.514; dominant model: OR 1.179, 95% CI 1.058-1.315; recessive model: OR 1.209, 95% CI 1.063-1.375; allele comparison model: OR 1.154, 95% CI 1.061-1.256). In the stratified analyses, significantly increased stroke risks were indicated among Asians in all genetic models (homozygote model: OR 1.726, 95% CI 1.314-2.267; dominant model: OR 1.535, 95% CI 1.282-1.838; recessive model: OR 1.452, 95% CI 1.160-1.818; allele comparison model: OR 1.403, 95% CI 1.211-1.626).The present meta-analysis suggests that rs1801133 polymorphism contributes to the risk of stroke, of note, in Asian populations.

Allele frequency distribution of 1691G >A F5 (which confers Factor V Leiden) across Europe, including Slavic populations

The allele 1691A F5, conferring Factor V Leiden, is a common risk factor in venous thromboembolism. The frequency distribution for this allele in Western Europe has been well documented; but here data from Central, Eastern and South-Eastern Europe has been included. In order to assess the significance of the collated data, a chi-squared test was applied, and Tukey tests and z-tests with Bonferroni correction were compared. Results: A distribution with a North-Southeast band of high frequency of the 1691A F5 allele was discovered with a pocket including some Southern Slavic populations with low frequency. European countries/regions can be arbitrarily delimited into low (group 1, <2.8 %, mean 1.9 % 1691A F5 allele) or high (group 2, ≥2.8 %, mean 4.0 %) frequency groups, with many significant differences between groups, but only one intra-group difference (the Tukey test is suggested to be superior to the z-tests). Conclusion: In Europe a North-Southeast band of 1691A F5 high frequency has been found, clarified by inclusion of data from Central, Eastern and South-Eastern Europe, which surrounds a pocket of low frequency in the Balkans which could possibly be explained by Slavic migration. There seem to be no indications of variation in environmental selection due to geographical location.

The role of genetic risk factors in arterial ischemic stroke in pediatric and adult patients: a critical review

The incidence of arterial ischemic stroke (AIS) in childhood (about 2-13 per 100,000 children a year) is much lower than the incidence in the adult population. Still, adverse outcomes of acute brain ischemia in childhood include death (10% of AIS children), neurological sequel, epileptic seizures (over 50%) and recurrence (over 20%). The knowledge of childhood stroke etiopathogenesis is still insufficient and the diagnostic and therapeutic procedures--controversial. Risk factors for childhood stroke differ from those observed in adults due to differing exposure to external risk factors. The most frequently reported risk factors for pediatric ischemic stroke are cerebral arteriopathies and vascular malformations, cardiac diseases, infections, traumas and metabolic diseases. Because of its multifactorial etiology pediatric AIS probably has a multigenic inheritance pattern. The genetic susceptibility to AIS may be determined by specific polymorphic variants encoding markers of hemostasis regulation and they are some of the most important targets in searching for genetic determinants in pediatric AIS. The authors have reviewed the recent literature on risk factors of childhood ischemic stroke with the focus on genetic factors like polymorphisms of genes encoding coagulation factors II, V, VII and XIII, MTHFR, fibrinogen beta, and compared them with the results performed in adult patients.

Influence of the β-fibrinogen-455G/A polymorphism on development of ischemic stroke and coronary heart disease

BACKGROUND

Ischemic stroke (IS) and coronary heart disease (CHD) are two vascular disorders that are a common cause of death worldwide. Several studies have assessed the association of the β-fibrinogen-455G/A (FGB-455G/A) polymorphism and risk of IS and CHD, but the results are still inconsistent. Our study aimed to investigate whether the FGB-455G/A polymorphism was associated with susceptibility to IS and CHD by using meta-analysis.

METHODS

Relevant studies were identified from PubMed, Embase and four Chinese database up to July 2013.Data were analyzed and processed by Stata 11.2. A pooled OR with 95% CI was calculated to estimate the strength of the genetic association. Cumulative meta-analysis was performed to assess the tendency of pooled OR over time.

RESULTS

45 studies based on a total of 7238 cases and 7395 controls were included in our meta-analysis. The results indicated that the FGB-455G/A polymorphism is associated with the risk of IS when compared with the dominant model (OR=1.518, 95%CI=1.279-1.802 for AA+GA vs. GG). In the subgroup analysis by ethnicity, significantly elevated risks were associated with the A allele in Asians (OR=1.700, 95%CI=1.417-2.040), but not in Caucasians (OR=0.942, 95%CI=0.813-1.091). Both the hypertension and non-hypertension subgroups reached significant results, but no significance was found when stratified according to sex or subtype of IS. Results indicate that the FGB-455G/A polymorphism is associated with CHD (OR=1.802, 95%CI=1.445-2.246).

CONCLUSION

Our meta-analysis suggests that the FGB-455G/A polymorphism contributes to susceptibility to IS and CHD.

Genetic polymorphism of β-fibrinogen gene-455G/A can contribute to the risk of ischemic stroke

Many studies have investigated the association between the β-fibrinogen gene-455G/A (FGβ-455G/A) polymorphism and the risk of ischemic stroke. However, these evidences were inadequate to provide stronger conclusions because most studies were generally small. To shed light on these inconclusive findings, we conducted a large sample size meta-analysis of studies relating to the FGβ-455G/A polymorphism and the risk of ischemic stroke. Odds ratios with a 95 % confidence interval were used to investigate the association between FGβ-455G/A polymorphism and ischemic stroke. Publication bias was tested by Egger's test and funnel plot. Inconsistency index and Cochran's Q statistic were used to check heterogeneity. Cumulative and recursive cumulative meta-analyses were performed to provide a framework for updating a genetic effect from all of the included studies. Twenty-six independent publications with 4,070 cases and 4,649 controls were included in this meta-analysis. Results showed that the β-fibrinogen-455G/A polymorphism was significantly associated with the risk of ischemic stroke. The FGβ-455G/A polymorphism was found to be a risk factor for ischemic stroke in Asians and adults, while association was not observed for Caucasians and juveniles based on the small size and it may be necessary to conduct larger studies on them to investigate the association in the future. The cumulative meta-analysis indicated a decline from 1998 to 2003, and the results remained stable during the period 2004-2012. The results indicate that FGβ-455G/A polymorphism may be a susceptible predictor of ischemic stroke. More studies are needed to elucidate the relationship further.

The TT genotype of methylenetetrahydrofolate reductase 677C>T polymorphism increases the susceptibility to pediatric ischemic stroke: meta-analysis of the 822 cases and 1,552 controls

The 677C>T polymorphism within methylenetetrahydrofolate reductase (MTHFR) gene is related to an elevated level of homocysteine. Thus it may be considered as a genetic risk factor in ischemic stroke. Apparently studies of this type of polymorphism in childhood stroke have shown conflicting results. We performed meta-analysis of all the data that are available in relation with MTHFR polymorphism and the risk of ischemic stroke in children. We searched PubMed (last search dated December 2010) using "MTHFR polymorphism", "ischemic stroke" "child", "children", "pediatric stroke" as keywords and reference lists of studies and reviews on the topic. Finally, 15 case-control studies corresponded to the inclusion criteria for meta-analysis. These studies involved the total number of 822 children and adolescents after ischemic stroke and 1,552 control subjects. Fixed or random effects models were used depending on the heterogeneity between the studies. The association between ischemic stroke and 677C>T polymorphism within MTHFR gene was observed in three of the studies. The pooled analysis showed that TT genotype of MTHFR gene is more common in stroke patients than in controls (p = 0.0402, odds ratio = 1.57, 95 % confidence interval 1.02-2.41). The Egger's test did not reveal presence of a publication bias. The results based on a sizeable group of cases and controls have proved that the 677C>T polymorphism in MTHFR gene is associated with the development of ischemic stroke in children.

Prothrombotic genetic risk factors in stroke: a possible different role in pediatric and adult patients

The role of thrombophilia in the pathogenesis of stroke is still controversial, especially in the pediatric stroke. In order to examine the role of common thrombophilic mutations in children and adults with stroke, a case-control study was carried out in a group of 80 children and 73 younger adult patients. The control groups encompassed 100 healthy children and 120 healthy blood donors. Our results showed no significant differences in the frequency of factor V (FV) Leiden, FII G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T variants between patient groups and corresponding controls. According to our results, carriers of 677CT genotype have 3.62 higher risks to develop stroke in children than in adults (P < .001). The obtained data indicate that heterozygosity for MTHFR C677T variant represents a possible important risk factor for pediatric stroke and suggest a different role of this gene variant in etiology of stroke in pediatric and adult patients.

Inherited thrombophilia in childhood arterial stroke: data from Lebanon

Pediatric ischemic stroke still represents a burden, and more than half of the survivors will experience cognitive or motor disabilities. The objective of this study was to investigate the role of thrombophilia in a cohort of children with arterial ischemic stroke. The records of infants and children with clinically and radiologically confirmed stroke were reviewed. Patients with venous or perinatal stroke were not included. Thirty-three patients were diagnosed with arterial ischemic stroke. The male/female ratio was 1.75:1. The median age was 4 years. The most frequent clinical manifestations were hemiparesis (54.5%) and seizures (33.3%). Genetic thrombophilia testing was available on 24 patients. Nine of the 24 patients (37.5%) were heterozygous for factor V Leiden. None of the patients carried the factor II G20210A variant. Ten patients (41.7%) were heterozygous and 3 (12.5%) were homozygous for methylenetetrahydrofolate reductase (MTHFR) C677T variant. Fifteen patients (62.5%) had one or more genetic polymorphism. Factor V Leiden was significantly associated with arterial ischemic stroke (P < 0.001). Stroke recurred in 2 children with multiple risk factors and MTHFR C677T mutation. Factor V Leiden is one of the major genetic risk factors for pediatric arterial ischemic stroke in Lebanon. MTHFR C677T was prevalent among patients with recurrent stroke.

The effect of four hemostatic gene polymorphisms on the outcome of septic critically ill patients

Genetic variants of hemostatic factors leading to prothrombotic phenotypes of hypercoagulability and hypofibrinolysis might affect prognosis of septic critically ill patients. Our aim was to evaluate the effect of four hemostatic genetic variants, namely fibrinogen-beta-455G/A, factor XIII (FXIII) V34L, plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphisms and factor V Leiden (FVL) mutation on survival of critically ill patients with severe sepsis or septic shock. A prospective, observational study in an 18-bed general ICU included 73 patients with severe sepsis or septic shock. Epidemiological, laboratory data and comorbidities along with severity scores were recorded. Genotyping for fibrinogen-beta-455G/A, FXIII V34L and PAI-1 4G/5G polymorphism and FVL mutation was carried out in all patients. The primary outcomes were the 28-day and the 90-day survival. Age, septic shock, severity indexes, prior steroid use and arterial pH were identified as predictors of the 28-day and 90-day survival in both the univariate and the multivariate models. On the contrary, none of the examined polymorphisms was found to significantly affect either the 28-day or the 90-day survival. Our data suggest that the importance of these hemostatic polymorphisms as predictors of the prognosis of sepsis in critically ill patients is probably very small.

The effect of plasma homocysteine levels on clinical outcomes of patients with acute lung injury/acute respiratory distress syndrome

BACKGROUND

Several reports have shown that homocysteine promotes thrombosis by disturbing the procoagulant-anticoagulant balance, whereas alterations in coagulation and fibrinolysis have been suggested as important pathogenetic and prognostic determinants of mortality in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). The objective of the study was to evaluate the effect of plasma homocysteine levels on the outcomes of patients with ALI/ARDS.

METHODS

Sixty-nine consecutive ventilated patients with ALI/ARDS were studied. Blood samples were drawn within 3 days of clinical recognition of ARDS. Measurement of plasma homocysteine, vitamin B12, folate, creatinine, protein C and plasminogen-activator inhibitor-1 antigen levels, and genotyping of the methylenetetrahydrofolate reductase gene C677T and A1298C polymorphisms were carried out. The primary outcomes were 28- and 90-day mortality, whereas secondary outcomes included nonpulmonary organ failure-free days, liberation from mechanical ventilation up to day 28, and ventilator-free days during the 28 days after enrollment.

RESULTS

In the multivariable analysis, plasma homocysteine concentration adjusted for age, Acute Physiology and Chronic Health Evaluation II score, methylenetetrahydrofolate reductase C677T and A1298C polymorphisms, and levels of plasminogen-activator inhibitor-1 antigen, protein C, creatinine, vitamin B12, and folate was not found to affect significantly mortality at 28 and 90 days (P = 0.39 and P = 0.83, respectively), days without organ failure besides lungs (P = 0.38), the probability of being free from mechanical ventilation at day 28 (P = 0.63), and days without ventilation assistance (P = 0.73).

CONCLUSION

Our data suggest that increased plasma homocysteine levels, either alone or in synergy with other thrombophilic risk factors, do not seem to adversely affect the prognosis in patients with ALI/ARDS.

The T allele of the 677C>T polymorphism of methylenetetrahydrofolate reductase gene is associated with an increased risk of ischemic stroke in Polish children

Ischemic stroke is a very rare and multifactorial disease in children. The aim of the study was to analyze the relationship between the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism and stroke in Polish children and to observe whether there is any significant transmission of MTHFR alleles from heterozygous parents to their affected offspring. We analyzed 64 patients with stroke, 122 parents, and 59 healthy children. The MTHFR polymorphism was genotyped using polymerase chain reaction (PCR)-restriction fragment length polymorphism. The T allele was more frequent in the stroke group (38%) than in controls (25%, P = .029, odds ratio = 1.84). We also found higher frequency of T allele in male patients compared to male controls (46% vs. 25%, P = .009, odds ratio = 2.53). The number of T allele carriers was again more prevalent in boys with stroke (71%) than in healthy boys (45%, P = .023, odds ratio = 3.09). The T allele was significantly transmitted in male patients (P < .019). We conclude that the MTHFR 677C>T polymorphism may be considered as a genetic risk factor of childhood stroke, especially in boys.

Genetic risk factors for arterial ischemic stroke in children: a possible MTHFR and eNOS gene-gene interplay?

In order to investigate the influence of genetic factors in childhood stroke, we compared the distributions of mutations/ polymorphisms affecting hemostasis and/or endothelial function (factor V [FV] Leiden, factor II [FII] G20210A, methylenetetrahydrofolate reductase [MTHFR] C677T, angiotensin-converting enzyme [ACE] insertion/deletion [ID], and endothelial nitric oxide synthase [eNOS] G894T) among children with stroke and controls. A total number of 26 children with arterial ischemic stroke and a control group of 50 healthy children were included in the study. No statistically significant differences in allelic and genotypic distribution were detected in comparisons between groups. However, when combined genotypes were analyzed, statistical significance was observed for the association of MTHFR CT and eNOS TT gene variants. The results of our study suggest that this genotype combination represents a risk factor of 7.2 (P = .017) for arterial ischemic stroke in children.

Posterior cerebral artery occlusion after Mycoplasma pneumoniae infection associated with genetic defect of MTHFR C677T

Cerebral artery occlusion in childhood, particularly in the posterior circulation, is a rare neurological complication of Mycoplasma pneumoniae infection. A genetic defect in the methylenetetrahydrofolate reductase gene could result in hyperhomocysteinemia and increased risk of stroke. We report a patient with posterior cerebral artery occlusion after Mycoplasma pneumoniae infection associated with a homozygous, methylenetetrahydrofolate reductase gene mutant type.

Inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine

OBJECTIVE

The aim of this study was to investigate the prevalence and possible association of inherited prothrombotic risk factors in children with stroke, transient ischemic attack, or migraine.

METHODS

We performed genotypic analysis for factor V G1691A, factor II G20210A, methylenetetrahydrofolate reductase C677T, and 4 common platelet glycoprotein polymorphisms (human platelet alloantigen-1, -2, -3, and -5) in 150 children <18 years of age with established diagnoses of stroke, transient ischemic attack, or migraine. Children were classified into 5 groups, namely, childhood arterial ischemic stroke (N = 33), perinatal arterial ischemic stroke (N = 26), hemorrhagic stroke (N = 20), transient ischemic attack (N = 36), and migraine (N = 35). The control group consisted of 112 children < or =18 years of age from the same geographical region who had no history of neurologic or thromboembolic diseases.

RESULTS

Heterozygosity for factor V G1691A was associated with approximately sevenfold increased risk for arterial ischemic stroke, perinatal arterial ischemic stroke, and transient ischemic attack. Increased risk for transient ischemic attack was found in carriers of the human platelet alloantigen-2b allele, human platelet alloantigen-5a/b genotype, and combined human platelet alloantigen-2b and human platelet alloantigen-5b genotype. The presence of the human platelet alloantigen-2b allele was associated with a 2.23-fold increased risk for migraine, whereas carriers of the human platelet alloantigen-3b allele had a lower risk for arterial ischemic stroke than did carriers of the human platelet alloantigen-3a allele.

CONCLUSIONS

Factor V G1691A has an important role in susceptibility to arterial ischemic stroke, both in the perinatal/neonatal period and in childhood, as well as transient ischemic attacks. A minor impact of human platelet alloantigen polymorphisms suggests that platelet glycoprotein polymorphisms may increase the risk of transient ischemic attacks and migraine, but this should be confirmed in larger studies.

Factor V Leiden and Antiphospholipid Antibodies in Either Mothers or Infants Increase the Risk for Perinatal Arterial Ischemic Stroke

Background and Purpose— The objective was to investigate the role of infant and maternal thrombophilia in a cohort of mothers and infants presenting with perinatal arterial ischemic stroke.

Methods— Forty-seven infants with clinically and radiologically confirmed perinatal arterial ischemic stroke underwent thrombophilia workup: factor V Leiden (FVL), PII20210A mutation, Methylene-tetrahydrofolate reductase 677T polymorphism, protein C, protein S, antithrombin, FVIII, and antiphospholipid antibodies. Thrombophilia data were available for 23 mother–infant pairs and compared with control populations to evaluate the risk for PAS.

Results— Thirty of 47 (64%) infants and 15 of 22 mothers (68%) had evidence of thrombophilia. In 18 of 23 (78%) mother–infant pairs, there was at least 1 thrombophilic risk factor, but 15 pairs were mismatched in pathology. Among infants, FVL, protein C deficiency, and presence of antiphospholipid antibodies prevailed (OR, 4.2; 95% CI, 1.5–11.3; OR, 12.2; 95% CI, 2.5–59.9; OR, 4.1; 95% CI, 1.4–12.2, respectively). Interestingly FVL prevailed in almost one-third of mothers (OR, 8.5; 95% CI, 4.1–17.5) and 18% of mothers had antiphospholipid antibodies (OR, 3.8l; 95% CI, 1.5–10.0).

Conclusions— Maternal and neonatal thrombophilia, especially presence of FVL or antiphospholipid antibodies, may be important in the pathogenesis of perinatal arterial ischemic stroke. The nature of thrombophilic mother–infant risk potential interactions warrants further investigation.

The impact of the PAI-1 4G/5G polymorphism on the outcome of patients with ALI/ARDS

INTRODUCTION

Increased levels of plasminogen activator inhibitor-1 (PAI-1) have been associated with worse outcome in ALI/ARDS. A single guanosine insertion/deletion (4G/5G) polymorphism in the promoter region of the PAI-1 gene, may play an important role in the regulation of PAI-1 expression. The objective of the study was to evaluate the effect of this polymorphism on the outcome of critically ill patients with ALI/ARDS.

MATERIALS AND METHODS

52 consecutive ventilated patients with ALI/ARDS were studied. Bronchoalveolar lavage was performed within 48 hours from diagnosis. Measurement of plasma and BALF PAI-1 activity and D-dimers levels, and 4G/5G genotyping of PAI-1 were carried out. The primary outcome was 28-day mortality, and secondary outcomes included organ dysfunction and ventilator-free days.

RESULTS

17 patients were homozygotes for the 4G allele. Severity scores were not different between subgroups upon study enrollment. 28-day mortality was 70.6% and 42.9% for the 4G-4G and the non-4G-4G patients, respectively (p=0.06). PAI-1 activity levels and D-dimer in plasma and BALF were not significantly different between the 4G-4G and the non-4G-4G subgroups. In the multivariate analysis, genotype 4G/4G was the only variable independently associated with 28-day mortality (Odds Ratio=9.95, 95% CI: 1.79-55.28, p=0.009). Furthermore, genotype 4G/4G and plasma PAI-1 activity levels were independently negatively associated with ventilator free days (p=0.033 and p=0.008, respectively).

CONCLUSIONS

ALI/ARDS patients, homozygous for the 4G allele of the PAI-1 gene, experienced higher 28-day mortality. This genotype was associated with a reduction in the number of days of unassisted ventilation and was inversely associated with the number of days without organ failure.

Genetic polymorphisms for the study of multifactorial stroke

Single-gene disorders explain only a minority of stroke cases. Stroke represents a complex trait, which is usually assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies, with controversial results. Therefore, it is difficult for the clinician to establish the validity and the level of clinical applicability of the previously reported associations between genetic factors and stroke. This review is an update and an extensive analysis of the more recent association studies conducted in stroke. We evaluated a number of studies on several candidate genes (including F5, F2, FGA/FGB/FGG, F7, F13A1, vWF, F12, SERPINE1, ITGB3/PLA1/PLA2/ITGA2B, ITGA2, GP1BA, ACE, AGT, NOS3, APOE, LPL, PON1, PDE4D, ALOX5AP, MTHFR, MTR, and CBS), providing a final panel of genes and molecular variants. We categorized this panel in relation to the degree of association with stroke, supported by the results of meta-analyses and case-control studies. Our findings could represent a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

beta-Fibrinogen Gene -455 G/A Polymorphism in Korean Ischemic Stroke Patients

Background and Purpose

We investigated the relationship between the β-fibrinogen gene (FGB) -455 G/A polymorphism and plasma fibrinogen levels in Korean ischemic stroke patients. We also determined whether the frequency of the -455 G/A polymorphism differed between two subtypes of noncardioembolic stroke: large-artery atherosclerosis (LAA) and small-vessel occlusion (SVO).

Methods

A total of 267 patients with noncardioembolic stroke were enrolled. Plasma fibrinogen and other risk factors for stroke were evaluated. FGB -455 G/A genotypes were determined by polymerase chain reaction with restrictive enzyme Hae III and automatic DNA sequencing.

Results

The FGB -455 G/A polymorphism was significantly associated with an elevated plasma fibrinogen level (p<0.001). The frequency of the A allele in Korean stroke patients was 16.7%. However, the frequency of the -455 G/A polymorphism did not differ between LAA and SVO.

Conclusions

The plasma fibrinogen level might be affected by the -455 G/A polymorphism in noncardioembolic stroke patients. However, the LAA and SVO subtypes of ischemic stroke were not affected by the -455 G/A polymorphism.

Two cousins with neonatal stroke, PAI-1 4G variant and MTHFR A1298C mutation

The authors describe 2 female cousins with neonatal stroke. One was heterozygous for the plasminogen activator inhibitor-1 4G variant and compound heterozygous for the A1298C and C677T methylenetetrahydrofolate reductase mutations. Her cousin was homozygous for the plasminogen activator inhibitor-1 4G variant and heterozygous for the methylenetetrahydrofolate reductase A1298C and factor V Leiden mutations.