Prothrombin G20210A mutation is associated with young-onset stroke: the genetics of early-onset stroke study and meta-analysis

The Association of Prothrombin Gene G20210A Mutation with Recurrent Venous Thromboembolism: Evidence from a Meta-Analysis

OBJECTIVES

The prothrombin (PT) G20210A mutation is one of the most prevalent genetic variations associated with an increased susceptibility to the first episode of venous thromboembolism (VTE). However, it remains uncertain whether this inherited thrombophilic abnormality also poses a risk for recurrent VTE. This meta-analysis aimed to assess the relation of PT G20210A mutation to the risk of recurrent VTE.

METHODS

PubMed and Scopus were systematically searched for pertinent prospective studies. Relative risks (RR) and 95% confidence intervals (CI) were used to test the association. Sixteen studies, with 16,174 participants, were included.

RESULTS

Carriers of the G20210 A mutation were at increased risk of recurrent VTE (RR = 1.60, 95% CI = 1.20-2.14) compared to noncarriers; the increased risk was observed in heterozygotes (GA versus GG) (RR = 1.79, 95% CI = 1.24-2.57), but not in GA/AA mutation.

CONCLUSIONS

This association was found to be significant in the long term (≥5 years of follow-up), but not in the short term (<5 years of follow-up).

Genetic Variants Associated with High Susceptibility of Premature Ischemic Stroke

Background

Several polymorphisms had been associated with an increased risk of ischemic stroke, but results are inconclusive. The aim of this study was to examine the association between AGTR1 A1166C and TSP-1 N700S polymorphisms and ischemic stroke in a young Mexican population.

Methods

In a case-control study, 250 patients ≤ 45 years of age with ischemic stroke and 250 controls matched by age and gender were included. The polymorphisms were determined in all participants by polymerase chain reaction.

Results

There were statistical differences in genotype distribution (p = 0.01) and allele frequency (p = 0.001) of AGTR1 A1166C polymorphism. In contrast, there was a similar genotype distribution (p = 0.96) and allele frequency (p = 0.76) of the TSP1 N700S genetic variant between groups. Hypertension (p = 0.03), smoking (p = 0.02), and family history of atherothrombotic disease (p = 0.04) were associated with stroke, but not diabetes (p = 0.30) and dyslipidemia (p = 0.08).

Conclusions

This is the first study in Mexican population to explore several genetic variants in young patients with ischemic stroke. Our results suggest that polymorphisms in the renin-angiotensin-aldosterone system could contribute to premature hypertension, endothelial dysfunction, atherothrombosis, vasoconstriction, smooth muscle cell migration, and proliferation. In contrast, polymorphisms in the coagulation factors are not associated with ischemic stroke. Environmental factors such as diabetes and dyslipidemia could be less important in the pathogenesis of ischemic stroke at a young age. We suggest that those polymorphisms should be determined in individuals with a family history of thrombosis to avoid the stroke development. Therefore, genotype-environmental combination could determine several possible phenotypes at different moments in life.

Venous thromboembolism-related genetic determinant F11 rs4253417 is a potential prognostic factor in ischaemic stroke

Ischaemic stroke (IS) and venous thromboembolism (VTE) are two forms of thromboembolism that, although distinct, seem to share numerous risk factors. Concerning genetic risk factors, while many VTE genetic markers have been reported, inclusively by genome-wide association studies (GWAS), the identification and validation of genetic determinants underlying IS pathogenesis have been challenging. Considering that IS and VTE shared biological pathways and aetiological factors, the severity of IS might be also influenced by VTE-related genetic variants. Thus, the present study was designed to analyse the impact of six VTE GWAS-identified genetic variants on the clinical outcome of 363 acute IS patients. Results revealed that the single-nucleotide polymorphism (SNP) F11 rs4253417 was an independent predictor of the 5-year risk of death among patients with total anterior circulation infarct (TACI). Namely, the ones carrying the SNP C allele presented a fourfold increase in the 5-year risk of death compared to TT genotype carriers (CC/CT vs. TT; adjusted HR, 4.240; 95% CI, 1.260-14.270; P = 0.020). This SNP is known to be associated with coagulation factor XI (FXI) levels, thus with implications in haemostasis and inflammation. As such, F11 rs4253417 might be a promising prognostic biomarker among TACI patients to aid in clinical decision-making. However, additional investigation is required to confirm the study's results and dissect the underlying mechanisms.

In silico identification of molecular mechanisms for stroke risk caused by heavy metals and their mixtures: sponges and drugs involved

This study used various approaches and databases to evaluate the molecular processes and identify miRNA sponges and drugs associated with the development of stroke caused by heavy metals and their combinations. We found that the genes ALB (albumin), IL1B (Interleukin-1β), F2 (coagulation factor II), APOA1 (apolipoprotein A1), IL6 (Interleukin 6), and NOS2 (nitric oxide synthase 2) were linked to the development of strokes by 18 chemicals and a combination of cadmium, copper, and lead. These results may point to the significance of detoxification and neuroinflammation in stroke as well as the potential for targeting these genes in future stroke therapies. ALB and IL1B were the most common and significant genes. The "selenium micronutrient network," "vitamin B12 metabolism," and "folate metabolism" were shown to be the most significant pathways connected to the risk of stroke brought on by combined heavy metals. The two main cellular elements that may increase the risk of stroke caused by heavy metals were discovered to be "blood microparticle" and "endoplasmic reticulum lumen." We also observed an important chromosome (chr7p15.3), two transcription factors (NFKB2 [nuclear factor kappa B subunit 2] and NR1I2 [nuclear receptor subfamily 1 group, member 2]), and four microRNAs (hsa-miR-26a-5p, hsa-miR-9-5p, hsa-miR-124-3p, and hsa-miR-155-5p) associated with stroke caused by combined heavy metals. Additionally, for these miRNAs, we created and examined in silico microRNA sponge sequences. Triflusal and andrographolide have been identified as potential treatments for heavy metal-induced stroke. Taken together, heavy metals may be a significant contributor to the pathophysiology of stroke, but further investigation into the precise molecular pathways implicated in stroke pathophysiology is required to corroborate these findings.

Dilemmas in hematology: consults in patients with arterial thrombosis

Arterial thrombotic events, particularly ischemic stroke and myocardial infarction, are common, and mostly occur due to atherosclerotic disease or arrhythmias. The diagnosis and management of the majority of such events occurs without the involvement of a hematologist, following established guidelines or pathways. In this review, we discuss 3 scenarios in which optimal management is less certain. These scenarios concern patients with a left ventricular thrombus, in whom the duration and choice of anticoagulant has been debated, patients with ischemic stroke and a patent foramen ovale, in whom the role of patent foramen ovale closure requires careful consideration, and the role of thrombophilia testing in young patients after a stroke or myocardial infarction, which remains an area of contention. We consider the available evidence and published guidelines in order to provide a practical, evidence-based approach to these 3 clinical scenarios.

Factor V Leiden, Factor II, Protein C, Protein S, and Antithrombin and Ischemic Strokes in Young Adults: A Meta-Analysis

Ischemic strokes are one of the leading causes of death worldwide. The aim of this meta-analysis is to elaborate on the role of inherited predisposition to thrombophilia in the etiology of ischemic strokes in young adults. The keywords factor V Leiden (FVL), factor II, prothrombin (PT), protein C (PC), protein S (PS), antithrombin (AT), ischemic stroke, and young were used to search different databases. We selected studies with participants who were between 18 and 65 years. A total of 104 studies were eligible for inclusion in the meta-analysis. All the studied genetic markers were risk factors for ischemic stroke according to our results (FVL OR = 1.74; PT OR = 1.95; PC OR = 10.20; PS OR = 1.74; AT OR = 3.47; p < 0.05). There was moderate heterogeneity for most of the results, and subgroup analyses were conducted by dividing the studies according to the geographic location, gender ratio, and selection criteria of the performed study. There were no significant differences between the groups, but different geographic location was a probable source of heterogeneity. All of the studied markers—FVL, prothrombin, PC, PS, and AT—were significantly associated with increased risk of ischemic stroke in young adults and, if tested, could improve the quality of care.

Contribution of Common Genetic Variants to Risk of Early-Onset Ischemic Stroke

BACKGROUND AND OBJECTIVES

Current genome-wide association studies of ischemic stroke have focused primarily on late-onset disease. As a complement to these studies, we sought to identify the contribution of common genetic variants to risk of early-onset ischemic stroke.

METHODS

We performed a meta-analysis of genome-wide association studies of early-onset stroke (EOS), ages 18-59 years, using individual-level data or summary statistics in 16,730 cases and 599,237 nonstroke controls obtained across 48 different studies. We further compared effect sizes at associated loci between EOS and late-onset stroke (LOS) and compared polygenic risk scores (PRS) for venous thromboembolism (VTE) between EOS and LOS.

RESULTS

We observed genome-wide significant associations of EOS with 2 variants in ABO, a known stroke locus. These variants tag blood subgroups O1 and A1, and the effect sizes of both variants were significantly larger in EOS compared with LOS. The odds ratio (OR) for rs529565, tagging O1, was 0.88 (95% confidence interval [CI]: 0.85-0.91) in EOS vs 0.96 (95% CI: 0.92-1.00) in LOS, and the OR for rs635634, tagging A1, was 1.16 (1.11-1.21) for EOS vs 1.05 (0.99-1.11) in LOS; p-values for interaction = 0.001 and 0.005, respectively. Using PRSs, we observed that greater genetic risk for VTE, another prothrombotic condition, was more strongly associated with EOS compared with LOS (p = 0.008).

DISCUSSION

The ABO locus, genetically predicted blood group A, and higher genetic propensity for venous thrombosis are more strongly associated with EOS than with LOS, supporting a stronger role of prothrombotic factors in EOS.

Potential Embolic Sources Differ in Patients With Embolic Stroke of Undetermined Source According to Age: A 15-Year Study

Introduction

Understanding the potential embolic source in young patients with ESUS may improve the diagnosis and treatment of such patients.

Hypothesis

Potential embolic sources (PES) differ in young vs. older patients with ESUS, and, therefore, not all patients with ESUS have the same risk profile for stroke recurrence.

Methods

Young patients (age 18-49) with ESUS, who were admitted to our stroke center from 2006 to 2019, were identified retrospectively and matched with next consecutive older patients (age 50-99) with ESUS by admission date. PES were categorized as atrial cardiopathy, AFib diagnosed during follow-up, left ventricular disease (LVD), cardiac valvular disease (CVD), PFO or atrial septal aneurysm (ASA), and arterial disease. Patients, who had cancer or thrombophilia, were excluded. The type and number of PES and stroke recurrence rates were determined and compared between young and older patients.

Results

In young patients (55.3% women, median age 39 years), the most common PES was PFO/ASA, and the rate of other PES was low (2-7%). Half of the young patients (54.1%) had a single PES, only 10% had multiple PES, and 35.3% of young patients did not have any PES identified. In older patients (41.7% women, median age 74 years), the 3 most common PES were atrial cardiopathy (38.1%), LVD (35.7%), and arterial disease (23.8%). Nearly half of older patients (42.9%) had multiple PES. The rate of stroke recurrence tended to be lower in young patients as compared to older patients (4.9 vs. 11.4%, p = 0.29). During a median follow-up of 3 years, only 3 young patients (4.9%) had a recurrent stroke, and two of them had unclosed PFO. There were no recurrent strokes among young patients with no PES identified.

Conclusions

It was noted that PES differ in patients with ESUS according to age and differences in recurrence. PFO is the only common PES in young patients with ESUS. Future studies prospectively evaluating PES in both age groups are needed.

Thrombophilia Testing After Ischemic Stroke: Why, When, and What?

Thrombophilia testing is frequently performed after an ischemic stroke, particularly when cryptogenic. However, there is minimal evidence supporting a significant association between most conditions assessed through thrombophilia testing and ischemic stroke, and the rationale for thrombophilia testing in many clinical situations remains uncertain. In this topical review, we review and contextualize the existing data on the risks, predictors, and outcomes of thrombophilic conditions in patients with ischemic stroke. We report that inherited thrombophilias have an uncertain relationship with ischemic stroke. Conversely, antiphospholipid syndrome, an acquired immune-mediated thrombophilia, seems to be a strong risk factor for arterial thromboembolic events, including ischemic stroke, and especially among young patients. Our findings suggest that certain circumstances may warrant targeted thrombophilia testing, such as stroke in the young, cryptogenic stroke, and high estrogen states. Future prospective studies should investigate the utility and cost effectiveness of thrombophilia testing in various stroke settings, including among patients with patent foramen ovale; as well as the optimal secondary stroke prevention regimen in patients with confirmed thrombophilia, particularly if no other potential stroke mechanism is identified.

Ischemic Stroke in Young Adults

PURPOSE OF REVIEW

This article reviews current knowledge on epidemiology, risk factors and causes, diagnostic considerations, management, and prognosis of ischemic stroke in young adults (those 55 years old and younger).

RECENT FINDINGS

The incidence of ischemic stroke in young adults has been increasing since the 1980s, which has occurred in parallel with increasing prevalence of vascular risk factors and substance abuse among the younger population. Young adults have a considerably wider range of risk factors than older patients, including age-specific factors such as pregnancy/puerperium and oral contraceptive use. Behavioral risk factors such as low physical activity, excess alcohol consumption, and smoking are factors as well. More than 150 identified causes of early-onset ischemic stroke exist, including rare monogenic disorders. Several recent advances have been made in diagnosis and management of stroke in young adults, including molecular characterization of monogenic vasculitis due to deficiency of adenosine deaminase 2 and transcatheter closure of patent foramen ovale for secondary prevention. Compared with the background population of the same age and sex, long-term mortality in patients remains fourfold higher with cardiovascular causes underlying most of the deaths. The cumulative rate of recurrent stroke extends up to 15% at 10 years. Patients with atherosclerosis, high-risk sources of cardioembolism, and small vessel disease underlying their stroke seem to have the worst prognosis regarding survival and recurrent vascular events. Young stroke survivors also often have other adverse outcomes in the long term, including epilepsy, pain, cognitive problems, and depression.

SUMMARY

Systematic identification of risk factors and causes and the motivation of patients for long-term prevention and lifestyle changes are of utmost importance to improve the prognosis of early-onset ischemic stroke.

Association of G20210A Prothrombin Gene Mutation and Cerebral Ischemic Stroke in Young Patients

Ischemic stroke is an acute episode of neurological dysfunction resulting from the focal brain and spinal cord infarction. Many etiologies have been reported and vary significantly with the age of the patients. This study aims to show the association of G20210A prothrombin gene mutation and cerebral ischemic stroke in young patients. The prothrombin gene mutation is the second most common inherited thrombophilia after the factor V mutation. In this single missense mutation, guanine is substituted by adenine base pair in the nucleotide position 20210 of the 3'-untranslated region of the prothrombin gene, resulting in abnormal thrombin production predisposing to both arterial or venous thrombosis. Forty-seven relevant articles were selected after a thorough screening process using a regular keyword 'G20210A Prothrombin' and/or 'Ischemic Stroke' mostly from the PubMed database. We included the studies that are published in the last 22 years with patients age ≤57 years. This review article depicts the association of G20210A prothrombin gene mutation with ischemic stroke in young patients irrespective of ethnicity and zygosity status of their genotype. However, more multicenter prospective studies are needed to better understand the application of prothrombin gene mutation in predicting the associated risk of ischemic stroke in young patients and its importance in deciding the patients' treatment or prognosis.

Biomarkers for ischemic stroke subtypes: A protein-protein interaction analysis

According to the Trial of Org 10172 in Acute Stroke Treatment, ischemic stroke is classified into five subtypes. However, the predictive biomarkers of ischemic stroke subtypes are still largely unknown. The utmost objective of this study is to map, construct and analyze protein-protein interaction (PPI) networks for all subtypes of ischemic stroke, and to suggest the predominant biological pathways for each subtypes. Through 6285 protein data retrieved from PolySearch2 and STRING database, the first PPI networks for all subtypes of ischemic stroke were constructed. Notably, F2 and PLG were identified as the critical proteins for large artery atherosclerosis (LAA), lacunar, cardioembolic, stroke of other determined etiology (SOE) and stroke of undetermined etiology (SUE). Gene ontology and DAVID analysis revealed that GO:0030193 regulation of blood coagulation and GO:0051917 regulation of fibrinolysis were the important functional clusters for all the subtypes. In addition, inflammatory pathway was the key etiology for LAA and lacunar, while FOS and JAK2/STAT3 signaling pathways might contribute to cardioembolic stroke. Due to many risk factors associated with SOE and SUE, the precise etiology for these two subtypes remained to be concluded.

High prevalence of inherited thrombophilia and antiphospholipid syndrome in myocardial infarction with non-obstructive coronary arteries: Comparison with cryptogenic stroke

BACKGROUND

A role of thrombophilia in myocardial infarction with non-obstructive coronary arteries (MINOCA) is unclear. We investigated thrombophilic factors in MINOCA patients versus those following cryptogenic stroke (CS), a well-established indication for thrombophilia screening.

METHODS

In a prospective cross-sectional study, we assessed 84 consecutive patients (median age: 45.5 years) at least 3 months after MINOCA. Age-matched CS patients (n = 84) and published data on general population served as controls. Thrombophilia screening involved inherited thrombophilia (factor V Leiden, prothrombin G20210A mutation, deficiency of protein C, protein S or antithrombin), antiphospholipid syndrome (APS), along with factor VIII >150%, homocysteine ≥15 μM and lipoprotein (a) >30 mg/dl.

RESULTS

Compared to CS, MINOCA were more often males (60.7 vs 33.3%, P < 0.001), obese (34.5 vs 17.9%, P = 0.014), smokers (51.2 vs 35.7%, P = 0.043) and had family history of myocardial infarction (27.4 vs 6.0%, P < 0.001). Inherited thrombophilia occurred in 20 (23.8%) MINOCA patients and in 13 (15.5%) with CS (P = 0.17), without any difference in the parameters except for elevated lipoprotein (a) that was less common in MINOCA (21.4 vs 39.3%, P = 0.012). APS was found in 13 (15.5%) of MINOCA patients, mostly in a single-positive form. APS was diagnosed less frequently in STEMI (2.5 vs 27.3% for NSTEMI, P = 0.002) and MINOCA patients aged ≤50 years (5.7 vs 32.3% for older subjects, P = 0.003).

CONCLUSIONS

MINOCA patients exhibit high prevalence of thrombophilia including APS, similar to that in CS. Our first comprehensive thrombophilia testing in MINOCA supports its clinical relevance and the need for long-term anticoagulation for some abnormalities, especially APS.

Extended Risk Factors for Stroke Prevention

Stroke causes disability and high mortality, while it can be prevented by increasing public awareness of risk factors. The common known risk factors are hypertension, atrial fibrillation, heart failure, smoking, alcohol consumption, low physical activity, overweight and hypercholesterolemia. However, the deep understanding of risk factors is limited. Moreover, more risk factor emerges in recent years. To further increase the awareness of risk factors for stroke prevention, this review indicates the reasonable application of antihypertensive agents according to the age-dependent changes of hypertension, and some new risk factors including chronic kidney disease, obstructive sleep apnea, migraine with aura, working environment, genetic factors and air pollution. Therefore, internal risk factors (e.g. heredity, hypertension, hyperglycemia) and external risk factors (e.g. working environment, air pollution) are both important for stroke prevention. All of these are reviewed to provide more information for the pre-hospital prevention and management, and the future clinical studies.

[Genetic characteristics of stroke]

In the recent years there is a growing interest in identification of additional genetic factors of stroke. A growing body of evidence supports the role of genetic factors in determining the risk of both hemorrhagic and ischemic stroke. The article considers the main genes associated with susceptibility to stroke and genetic polymorphisms associated with the disease. Genetic factors, modulating inflammation process, coagulation, lipid metabolism, NO formation, renin-angiotensin-aldosterone system and homeostasis play a significant role in stroke development. A comprehensive analysis of different genes associated with stroke may help to detect individuals with extremely high risk of stroke and implement timely preventive measures to decrease stroke burden.

[The association of hemostasis system genes with the development of ischemic stroke in patients under the age of 50 years]

AIM

To study an influence of polymorphic variants of hemostasis system genes on the risk of ischemic stroke (IS) in patients of the Slavic population under the age of 50 years.

MATERIAL AND METHODS

Ninety-two patients (19 women and 73 men), aged 18-50 years, were examined. The diagnosis of stroke was confirmed by neuroimaging (CT or MRI) in all patients. Polymorphic alleles of GP1BA, F2, F5 were studied by a real-time polymerase chain reaction using the TaqMan technology.

RESULTS AND CONCLUSION

An analysis of the GP1BA -5T/C polymorphism showed that it was associated with IS in young men, lacunar stroke and stroke due to thrombosis of the brachiocephalic arteries. This association was not found in young women. The F5 G1691A polymorphism was associated with lacunar stroke. The F2 G20210A polymorphism was associated with stroke due to thrombosis of the brachiocephalic arteries.

Genetics of the thrombomodulin-endothelial cell protein C receptor system and the risk of early-onset ischemic stroke

BACKGROUND AND PURPOSE

Polymorphisms in coagulation genes have been associated with early-onset ischemic stroke. Here we pursue an a priori hypothesis that genetic variation in the endothelial-based receptors of the thrombomodulin-protein C system (THBD and PROCR) may similarly be associated with early-onset ischemic stroke. We explored this hypothesis utilizing a multi-stage design of discovery and replication.

METHODS

Discovery was performed in the Genetics-of-Early-Onset Stroke (GEOS) Study, a biracial population-based case-control study of ischemic stroke among men and women aged 15-49 including 829 cases of first ischemic stroke (42.2% African-American) and 850 age-comparable stroke-free controls (38.1% African-American). Twenty-four single-nucleotide-polymorphisms (SNPs) in THBD and 22 SNPs in PROCR were evaluated. Following LD pruning (r2≥0.8), we advanced uncorrelated SNPs forward for association analyses. Associated SNPs were evaluated for replication in an early-onset ischemic stroke population (onset-age<60 years) consisting of 3676 cases and 21118 non-stroke controls from 6 case-control studies. Lastly, we determined if the replicated SNPs also associated with older-onset ischemic stroke in the METASTROKE data-base.

RESULTS

Among GEOS Caucasians, PROCR rs9574, which was in strong LD with 8 other SNPs, and one additional independent SNP rs2069951, were significantly associated with ischemic stroke (rs9574, OR = 1.33, p = 0.003; rs2069951, OR = 1.80, p = 0.006) using an additive-model adjusting for age, gender and population-structure. Adjusting for risk factors did not change the associations; however, associations were strengthened among those without risk factors. PROCR rs9574 also associated with early-onset ischemic stroke in the replication sample (OR = 1.08, p = 0.015), but not older-onset stroke. There were no PROCR associations in African-Americans, nor were there any THBD associations in either ethnicity.

CONCLUSION

PROCR polymorphisms are associated with early-onset ischemic stroke in Caucasians.

Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Triggers, Causes, and Outcome (SECRETO): Rationale and design

BACKGROUND

Worldwide, about 1.3 million annual ischaemic strokes (IS) occur in adults aged <50 years. Of these early-onset strokes, up to 50% can be regarded as cryptogenic or associated with conditions with poorly documented causality like patent foramen ovale and coagulopathies.

KEY HYPOTHESES/AIMS

(1) Investigate transient triggers and clinical/sub-clinical chronic risk factors associated with cryptogenic IS in the young; (2) use cardiac imaging methods exceeding state-of-the-art to reveal novel sources for embolism; (3) search for covert thrombosis and haemostasis abnormalities; (4) discover new disease pathways using next-generation sequencing and RNA gene expression studies; (5) determine patient prognosis by use of phenotypic and genetic data; and (6) adapt systems medicine approach to investigate complex risk-factor interactions.

DESIGN

Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO; NCT01934725) is a prospective multi-centre case-control study enrolling patients aged 18-49 years hospitalised due to first-ever imaging-proven IS of undetermined etiology. Patients are examined according to a standardised protocol and followed up for 10 years. Patients are 1:1 age- and sex-matched to stroke-free controls. Key study elements include centralised reading of echocardiography, electrocardiography, and neurovascular imaging, as well as blood samples for genetic, gene-expression, thrombosis and haemostasis and biomarker analysis. We aim to have 600 patient-control pairs enrolled by the end of 2018.

SUMMARY

SECRETO is aiming to establish novel mechanisms and prognosis of cryptogenic IS in the young and will provide new directions for therapy development for these patients. First results are anticipated in 2019.

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.

Ischemic Stroke in Young Adults of Northern China: Characteristics and Risk Factors for Recurrence

BACKGROUND

Young adults accounted for 10-14% of ischemic stroke patients. The risk factors may differ in this population from elder patients. In addition, the factors associated with stroke recurrence in this population have not been well investigated.

OBJECTIVE

The study aimed to investigate the characteristics and risk factors associated with recurrence of ischemic stroke in young adults.

METHODS

Clinical data of 1,395 patients of age 18-45 years who were treated between 2008 and 2014 in 3 centers located in northern China was reviewed. The first onset of stroke was taken as the initial events and recurrent stroke as the end point events. The end point events, age, gender, duration after first onset of stroke, history of disease, National Institutes of Health Stroke Scale (NIHSS) score at admission, Trial of Org 10172 in Acute Stroke Treatment classifications of the cause of stroke and adherence to medication were recorded. These factors were analyzed and compared between recurrence and non-recurrence group. Information about recurrent stroke was collected through clinical (readmission to hospital with ischemic stroke) or telephone follow-up survey. Logistic regression was used to analyze the risk factors of recurrence.

RESULTS

The most common causes of stroke were large vessel atherosclerosis and small vessel occlusion, followed by cardioembolism. NIHSS score at admission (OR 1.088; 95% CI 1.028-1.152; p = 0.004) were associated with recurrence.

CONCLUSIONS

Vascular disease, especially premature atherosclerosis, is the major risk factor for ischemic stroke in the young adult population of northern China. Timely screening of the cause of stroke with severe NIHSS score needs further attention.

Association Between the G20210A Polymorphism of Prothrombin Gene and Myocardial Infarction in Tunisian Population

The prothrombin is the precursor of the serine protease thrombin, a key enzyme in homeostasis. Prothrombin G20210A polymorphism (rs1799963) was described as a moderate risk factor for venous thrombosis because this mutation is associated with prothrombin elevated levels which may lead to an imbalance between the procoagulant, anticoagulant, and fibrinolytic system. 20210A carriers have an increased risk of thrombosis. In this study, we proposed to determine the prevalence of 20210A prothrombin variant among Tunisian population, and to evaluate the potential relevance of this variant with myocardial infarction. This study included 1290 unrelated Tunisians (1007 male and 283 female) divided in two groups: Four hundred and eighty-seven MI patients (mean age: 52.64 ± 8.98 years) and 803 apparently healthy controls (mean age: 51 ± 8.99). The prothrombin G20210A polymorphism was carried out by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) analysis. The distribution of genotypes was in accordance with Hardy-Weinberg equilibrium (p > 0.05). A significant difference in genotype distribution and allele frequency was observed between patients and controls. Male patients with MI had a frequency of 97 % for GG genotype and 3 % for GA+AA genotypes. The control group had a frequency of 99 % for the GG genotype and 1 % for the GA+AA genotypes which is significantly lower than the frequency found in patients (p = 0.01). The same genotype frequencies were found in women (p = 0.032). The MI patient group showed a significantly higher frequency of 20210A allele compared to controls 0.02 versus 0.01 [OR = 3.60 (95 % CI = 1.29-10.53), p = 0.005] in men and 0.015 versus 0.068 [OR = 4.68 (95 % CI = 1.60-14.26), p = 0.001] in women. Our work showed a significant but not independent association between the G20210A polymorphism of the prothrombin gene and MI in the Tunisian population.

Ischemic stroke in the young: Current perspectives on incidence, risk factors, and cardiovascular prognosis

About one-fourth of ischemic strokes occur in working-aged individuals in the high-income countries, with worldwide increasing incidence in this age group from 1980s to present. Recent evidence suggests that traditional vascular risk factors are more prevalent than previously suggested in young adult stroke patients and they accumulate with age particularly in men. Accordingly, relatively high rates of atherosclerotic changes have been detected in these patients. The strength of association of vascular risk factors has gone poorly studied, however. Many young patients with ischemic stroke have, in turn, no traditional risk factors, while they may harbor other conditions with weak or uncertain association with the stroke alone. These individual conditions often represent a risk factor that may be strictly young-age specific, more prevalent in younger than older stroke patients (e.g. patent foramen ovale), or more prevalent among the young in the population. Despite high rates of vascular risk factors and atherosclerotic changes, these findings do not translate to higher frequencies of identified classical stroke mechanisms. In fact, cryptogenic causes are markedly common and even more frequent among the very young patients. Limited randomized trial evidence exists to support secondary prevention decision-making in patients, yet they face an increased risk of death and future vascular events for years to come-dependent on risk factor profile and cause of the stroke. This review provides an overview of recent data on epidemiology, risk factors, and their strength of association in ischemic stroke in the young. Furthermore, the relationship between with the risk factors and cardiovascular outcomes and key features on the evidence related to secondary prevention will be discussed.