Methylenetetrahydrofolate reductase gene A222V polymorphism and risk of ischemic stroke

Relationship of Methylenetetrahydrofolate Reductase (MTHFR) C677T Variation With Susceptibility of Patients With Ischemic Stroke: A Meta-Analysis

Discovery and validation of genetic factors for multifactorial and polygenic disorders like stroke are needed to make progress in precision medicine. Although some traditional risk factors for stroke have been identified, they do not fully explain the pathophysiological mechanism of ischemic stroke. The research of genetic risk factors is becoming increasingly relevant in the understanding of stroke mechanisms and the finding of population-specific therapeutic targets. The methylenetetrahydrofolate reductase (MTHFR) gene is involved in homocysteine metabolism, and a high homocysteine level is a risk factor for stroke. Using a meta-analysis technique, we investigated the link between the MTHFR C677T gene polymorphism and the risk of ischemic stroke.

We used the electronic databases PubMed, Medline, Embase, and Google Scholar to find articles in the Journal of Stroke. If heterogeneity was more than 50%, pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model; otherwise, a fixed-effects model was used.

A total of 67 case-control studies with 17,704 cases and 21,981 controls met our inclusion criteria. The Asian population was represented by 41 studies, whereas the Caucasian population was represented by 26. Under the recessive model, a gene polymorphism at the 677 location of the MTHFR gene is related to an elevated risk of ischemic stroke (OR: 1.29, 95% CI: 1.22-1.37, P < 0.001).

People who have the MTHFR C677T gene polymorphism have a greater risk of stroke than people who do not.

Association of the methylenetetrahydrofolate reductase (MTHFR) gene variant C677T with serum homocysteine levels and the severity of ischaemic stroke: a case-control study in the southwest of China

OBJECTIVE

To determine whether the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism is linked to the risk of ischaemic stroke and circulating homocysteine (Hcy) levels in a Chinese population.

METHODS

This case-control study recruited angiogram-diagnosed patients with ischaemic stroke and healthy control subjects. The plasma Hcy concentrations were measured and the MTHFR C677T gene polymorphism was genotyped. The National Institutes of Health Stroke Scale (NIHSS) was used to assess the severity of the ischaemic stroke.

RESULTS

This study recruited 198 patients with ischaemic stroke and 168 controls. The TT genotype conferred a higher risk for ischaemic stroke than the CC genotype (odds ratio of 3.563; 95% confidence interval [CI] 1.412, 4.350). The T allele was the predisposing allele for ischaemic stroke. Hcy had an area under the receiver operating characteristic (ROC) curve of 0.624 (95% CI 0.530, 0.758). The ROC for Hcy demonstrated its usefulness in predicting ischaemic stroke. Hcy levels were not associated with ischaemic stroke severity as measured by the NIHSS.

CONCLUSION

The MTHFR C677T gene polymorphism affects circulating Hcy levels. The MTHFR C677T gene polymorphism and hyperhomocysteinaemia may play important roles in predicting the risk of ischaemic stroke.

Current State of Evidence: Influence of Nutritional and Nutrigenetic Factors on Immunity in the COVID-19 Pandemic Framework

The pandemic caused by the new coronavirus has caused shock waves in many countries, producing a global health crisis worldwide. Lack of knowledge of the biological mechanisms of viruses, plus the absence of effective treatments against the disease (COVID-19) and/or vaccines have pulled factors that can compromise the proper functioning of the immune system to fight against infectious diseases into the spotlight. The optimal status of specific nutrients is considered crucial to keeping immune components within their normal activity, helping to avoid and overcome infections. Specifically, the European Food Safety Authority (EFSA) evaluated and deems six vitamins (D, A, C, Folate, B6, B12) and four minerals (zinc, iron, copper and selenium) to be essential for the normal functioning of the immune system, due to the scientific evidence collected so far. In this report, an update on the evidence of the contribution of nutritional factors as immune-enhancing aspects, factors that could reduce their bioavailability, and the role of the optimal status of these nutrients within the COVID-19 pandemic context was carried out. First, a non-systematic review of the current state of knowledge regarding the impact of an optimal nutritional status of these nutrients on the proper functioning of the immune system as well as their potential role in COVID-19 prevention/treatment was carried out by searching for available scientific evidence in PubMed and LitCovid databases. Second, a compilation from published sources and an analysis of nutritional data from 10 European countries was performed, and the relationship between country nutritional status and epidemiological COVID-19 data (available in the Worldometers database) was evaluated following an ecological study design. Furthermore, the potential effect of genetics was considered through the selection of genetic variants previously identified in Genome-Wide Association studies (GWAs) as influencing the nutritional status of these 10 considered nutrients. Therefore, access to genetic information in accessible databases (1000genomes, by Ensembl) of individuals from European populations enabled an approximation that countries might present a greater risk of suboptimal status of the nutrients studied. Results from the review approach show the importance of maintaining a correct nutritional status of these 10 nutrients analyzed for the health of the immune system, highlighting the importance of Vitamin D and iron in the context of COVID-19. Besides, the ecological study demonstrates that intake levels of relevant micronutrients-especially Vitamins D, C, B12, and iron-are inversely associated with higher COVID-19 incidence and/or mortality, particularly in populations genetically predisposed to show lower micronutrient status. In conclusion, nutrigenetic data provided by joint assessment of 10 essential nutrients for the functioning of the immune system and of the genetic factors that can limit their bioavailability can be a fundamental tool to help strengthen the immune system of individuals and prepare populations to fight against infectious diseases such as COVID-19.

MTHFR Gene Polymorphisms Prevalence and Cardiovascular Risk Factors Involved in Cardioembolic Stroke Type and Severity

Background: Cardioembolic stroke (CES), generally known as the most severe subtype of ischemic stroke, is related to many factors, including diabetes mellitus (DM), hypertension (HTN), smoking, hyperlipidemia and atrial fibrillation (AF). Genetic mutations of the methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C have been recently associated with ischemic stroke. The purpose of this study was to analyze the prevalence of MTHFR gene polymorphisms correlated with cardiovascular risk factors in a selected population of patients with CES due to non-valvular AF (NVAF). Methods: This cross-sectional study was performed on 67 consecutive patients with acute cardioembolic stroke admitted to our hospital. The protocol included general physical examination, neurological clinical status and stroke severity evaluation, imagistic evaluation and genetic testing of MTHFRC677T and A1298C polymorphisms. Results: The prevalence of MTHFR polymorphisms in the study population was 38.2% for C677T and 40.3% for A1298C. The C677T mutation was significantly correlated with increased diastolic blood pressure (DBP) values (p = 0.007), higher total cholesterol (TC) (p = 0.003), low-density lipoprotein cholesterol (LDLc) (p = 0.003) and triglycerides (TGL) (p = 0.001), increased high-sensitive C-reactive protein (hsCRP) values (p = 0.015), HbA1c (p = 0.004) and left ventricle ejection fraction (LVEF) (p = 0.047) and lower high-density lipoprotein cholesterol (HDLc) (p < 0.001) compared to patients without this genetic variant. This genetic profile also included significantly higher CHA₂DS₂VASC (p = 0.029) and HASBLED (Hypertension, Abnormal liver/renal function, Stroke, Bleeding, Labile INR, Elderly age(>65 years), Drug/Alcohol usage history/Medication usage with bleeding predisposition) (p = 0.025) scores. Stroke severity in patients with MTHFRA1298C mutation was significantly increased when applying National Institutes of Health Stroke Scale (NIHSS) (p = 0.006) and modified Rankin scale (mRS) (p = 0.020) scores. The presence of A1298C mutation as a dependent variable was associated with significantly higher TGL values (odds ratio (OR) = 2.983, 95%CI = (1.972, 7.994)). Conclusions: The results obtained in this study demonstrate that MTHFR gene polymorphisms have a high prevalence in an NVAF cardioembolic stroke population. Moreover, an association between C677T mutation and stroke severity was highlighted. The C677T mutation in patients with NVAF was correlated with a higher incidence of cardiovascular comorbidities (hypertension HTN, heart failure (HF), dyslipidemia, type II diabetes mellitus (T2DM) with high HbA1c and increased inflammatory state). The A1298CMTHFR gene mutation was associated with a higher incidence of previous lacunar stroke and stroke recurrence rate, while dyslipidemia was the main cardiovascular comorbidity in this category.

A prospective cohort study of MTHFR C677T gene polymorphism and its influence on the therapeutic effect of homocysteine in stroke patients with hyperhomocysteinemia

BACKGROUND

Hyperhomocysteinemia (HHCY) is a risk factor for cardiovascular and cerebrovascular diseases. The C677T 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphism increases homocysteine (HCY) levels. This study analyzed the relationship between C677T MTHFR polymorphism and the therapeutic effect of lowering HCY in stroke patients with HHCY.

METHODS

Baseline data were collected from stroke patients with HHCY for this prospective cohort study. The C677T MTHFR genotype was detected by polymerase chain reaction-restriction fragment length polymorphism and the therapeutic effect to reduce HCY was compared.

RESULTS

Of 200 stroke patients 162 (81.0%) completed follow-up and were evaluated. Most of them responded well to treatment (103 cases, 63.5%), but 59 (36.4%) patients were in the poor efficacy group. There was a significant difference in terms of age (P < 0.001), hypertension (P = 0.041), hyperuricemia (P = 0.042), HCY after treatment (P < 0.001), and MTHFR genotype (P < 0.001) between the poor efficacy and effective groups, with increased frequency of the TT genotype in the poor efficacy group. Logistic regression showed that the T allele was associated with poor efficacy (OR = 0.733, 95%CI: 0.693, 0.862, P < 0.001). In the codominant model the TT genotype was associated with poor outcome (OR = 0.862, 95%CI: 0.767, 0.970, P = 0.017) and this was also the case in the recessive model (OR = 0.585, 95%CI: 0.462, 0.741, P < 0.001) but there was no association between CT and TT in the dominant model.

CONCLUSIONS

The T allele and TT genotype of the MTHFR C677T polymorphism was associated with poor HCY reduction treatment efficacy in stroke patients with HHCY.

TRIAL REGISTRATION

The registration number of the clinical trial is ChiCTR1800020048. Registration date: December 12, 2018.

Pathogenic variants in the ABCC6 gene are associated with an increased risk for ischemic stroke

Ischemic stroke causes a high mortality and morbidity worldwide. It results from a complex interplay of incompletely known environmental and genetic risk factors. We investigated the ABCC6 gene as a candidate risk factor for ischemic stroke because of the increased ischemic stroke incidence in the autosomal recessive disorder pseudoxanthoma elasticum, caused by biallelic pathogenic ABCC6 variants, the higher cardiovascular risk in heterozygous carriers and the established role of ABCC6 dysfunction in myocardial ischemia. We established segregation of a known pathogenic ABCC6 variant (p.[Arg1314Gln]) in 11/19 family members of an ischemic stroke patient in a large multigenerational family suffering from ischemic stroke and/or cardiovascular disease at a relatively young age. In an independent case-control study in 424 ischemic stroke patients and 250 healthy controls, pathogenic ABCC6 variants were 4.9 times more frequent (P = 0.036; 95% CI 1.11-21.33) in the ischemic stroke patient cohort. To study cellular consequences of ABCC6 deficiency in the brain, immunostaining of brain sections in Abcc6-deficient mice and wild-type controls were performed. An upregulation of Bmp4 and Eng and a downregulation of Alk2 was identified in Abcc6-/- mice, suggesting an increase in apoptosis and angiogenesis. As both of these processes are induced in ischemia, we propose that a pro-ischemic state may explain the higher risk to suffer from ischemic stroke in patients carrying a pathogenic ABCC6 variant, as this may lower the threshold to develop acute ischemic events in these patients. In conclusion, this study identified heterozygous ABCC6 variants as a risk factor for ischemic stroke. Further, dysregulation of Bmp (Bmp4, Alk2) and Tgfβ (Eng) signaling in the brain of Abcc6-/- mice could lead to a pro-ischemic state, lowering the threshold to develop acute ischemic events. These data demonstrate the importance of a molecular analysis of the ABCC6 gene in patients diagnosed with cryptogenic ischemic stroke.

Methylenetetrahydrofolate reductase gene C677T and A1298C polymorphisms and susceptibility to recurrent pregnancy loss

Several studies have investigated the link between two different polymorphisms (C677T and A1298T) of the gene encoding methylenetetrahydrofolate reductase (MTHFR) and the risk of recurrent pregnancy loss (RPL); however, the results remain controversial. This study aimed to provide greater insight into this debated topic. In the current study, two groups of pregnant women (group A: RPL women; group B: non-RPL women), each of which were subdivided further into two subgroups based on their gestational age, were screened for C677T and A1298T variants of the MTHFR gene. The resulting data were analyzed using receiver operating characteristic (ROC) curve and Z test methods to compare the two groups. These ROC curve and Z test analyses indicated that there were no differences between the groups regarding C677T and A1298T expression. RPL is primarily caused by mutations in prothrombin or factor V Leiden genes. However, a low percentage of RPL cannot be attributed to these mutations. In the last five years, research has focused on the MTHFR gene, the two major variants of which (C677T and A1298T) have been associated with an increased risk of cardiovascular diseases (thrombotic events) in homozygous individuals. In addition, these mutations may be related to an increased rate of neural tube defects in fetuses. While a link between MTHFR mutation and RPL may be expected based on previous findings, the present study indicated the absence of an association between the polymorphisms of the MTHFR gene and RPL risk.

[Analysis of the effect of N5, N10-methylenetetrahydrofolate reductase gene C(677)-->T polymorphism on the ischemic stroke development in persons with various risk factors]

The results ofMTHFR gene C(677)-->T (rs1801133) polymorphism determined in 170 patients with ischemic atherothrombotic stroke (IATS) and 124 healthy subjects (control group) are presented in the paper. It has been shown that in patients with IATS, the frequencies of main homozygotes (CC), heterozygotes (CT) and minor homozygotes (TT) are 52.4, 35.9, 11.8% (in control--46.0, 48.4, 5.6%, P = 0.044 by chi2-test). TT homozygotes have a greater chance of developing IATS than carriers of main C-allele (CT + CC) (OR = 2.3, CI = 0.911-5.449, P = 0.049). In the representatives of the Ukrainian population there is a relationship between the frequency of MTHFR gene C(677)-->T polymorphism genotypes and the risk of IATS. This connection is manifested in male patients, in persons with normal blood pressure, and in people who do not have the habit of smoking. The sex of the patients, body mass index, blood pressure and smoking affect the level of the studied polymorphism association with stroke.

Genetic polymorphisms of Chinese patients with ischemic stroke and concurrent stenoses of extracranial and intracranial vessels

The etiology of concurrent stenoses of extracranial and intracranial vessels in patients with ischemic stroke is poorly understood, but hereditary factors are believed to be important. We aimed to determine whether genetic polymorphisms affecting homocysteine and lipid metabolism are associated with concurrent stenoses. The genotypes of 191 Han Chinese patients with acute ischemic stroke, of whom 47 (25%) had concurrent stenoses, and 167 healthy control patients in Hong Kong were examined for the following polymorphisms: paraoxonase 1 (PON1) Q192R, methylenetetrahydrofolate reductase (MTHFR) A222V, glutamate-cysteine ligase catalytic-subunit (GCLC)-129C>T, and oxidized low-density lipoprotein receptor (OLR) 3' untranslated region C>T (rs1050283). The genotype distributions of PON1 Q192R and MTHFR A222V, which affect lipid and homocysteine metabolism, differed significantly between patients with stroke and healthy controls. The presence of at least one R allele in PON1 Q192R and a TT allele in OLR rs1050283 were associated with concurrent stenoses. We also identified a possible association between the presence of at least one V allele in MTHFR A222V and concurrent stenoses. This study shows that genetic polymorphisms affecting homocysteine and lipid metabolism are possible risk factors for stroke and concurrent stenoses.

Variants conferring risk of atrial fibrillation on chromosome 4q25

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans and is characterized by chaotic electrical activity of the atria. It affects one in ten individuals over the age of 80 years, causes significant morbidity and is an independent predictor of mortality. Recent studies have provided evidence of a genetic contribution to AF. Mutations in potassium-channel genes have been associated with familial AF but account for only a small fraction of all cases of AF. We have performed a genome-wide association scan, followed by replication studies in three populations of European descent and a Chinese population from Hong Kong and find a strong association between two sequence variants on chromosome 4q25 and AF. Here we show that about 35% of individuals of European descent have at least one of the variants and that the risk of AF increases by 1.72 and 1.39 per copy. The association with the stronger variant is replicated in the Chinese population, where it is carried by 75% of individuals and the risk of AF is increased by 1.42 per copy. A stronger association was observed in individuals with typical atrial flutter. Both variants are adjacent to PITX2, which is known to have a critical function in left-right asymmetry of the heart.

Metabolism of low-dose inorganic arsenic in a central European population: influence of sex and genetic polymorphisms

BACKGROUND

There is a wide variation in susceptibility to health effects of arsenic, which, in part, may be due to differences in arsenic metabolism. Arsenic is metabolized by reduction and methylation reactions, catalyzed by reductases and methyltransferases.

OBJECTIVES

Our goal in this study was to elucidate the influence of various demographic and genetic factors on the metabolism of arsenic.

METHODS

We studied 415 individuals from Hungary, Romania, and Slovakia by measuring arsenic metabolites in urine using liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICPMS). We performed genotyping of arsenic (+III) methyltransferase (AS3MT), glutathione S-transferase omega 1 (GSTO1), and methylene-tetrahydrofolate reductase (MTHFR).

RESULTS

The results show that the M287T (T-->C) polymorphism in the AS3MT gene, the A222V (C-->T) polymorphism in the MTHFR gene, body mass index, and sex are major factors that influence arsenic metabolism in this population, with a median of 8.0 microg/L arsenic in urine. Females < 60 years of age had, in general, higher methylation efficiency than males, indicating an influence of sex steroids. That might also explain the observed better methylation in overweight or obese women, compared with normal weight men. The influence of the M287T (T-->C) polymorphism in the AS3MT gene on the methylation capacity was much more pronounced in men than in women.

CONCLUSIONS

The factors investigated explained almost 20% of the variation seen in the metabolism of arsenic among men and only around 4% of the variation among women. The rest of the variation is probably explained by other methyltransferases backing up the methylation of arsenic.

Polymorphisms and vascular cognitive impairment after ischemic stroke

Environmental and genetic factors may both affect the risk of vascular cognitive impairment developing after a stroke. To identify factors affecting this risk, the cognitive status of 121 patients was examined 3 months after an ischemic stroke. In all patients and in 270 control subjects, 7 polymorphisms reported to affect risk of vascular ischemic disease were genotyped. In 51 patients (42.1%), vascular cognitive impairment resulted, defined by a Mini-Mental State Examination score of less than 24. These patients were older and more likely to be women. Alleles of none of the polymorphisms differed between patients with or without vascular cognitive impairment, except for glutamate-cysteine ligase modifier (GCLM) (odds ratio = 2.8, P = .006). When all stroke patients were considered, the GCLM genotype did not affect Mini-Mental State Examination scores. Testing the GCLM genotype in an independent group of stroke patients may determine whether this association with vascular cognitive impairment is genuine.

Association of gene polymorphism with genetic susceptibility to stroke in Asian populations: a meta-analysis

Stroke is a heterogeneous multifactorial disease and is thought to have a polygenic basis. Case-control studies on gene sequence variations have identified a number of potential genetic predisposition factors, but due to the conflicting results, uncertainty remains on the effect of these polymorphisms on risk for the development of stroke. To qualitatively and quantitatively assess the risk associated with different gene polymorphisms for stroke in Asian populations, we comprehensively searched and identified all the studies of association. Clinically overt case-control studies were selected only if neuroimaging had been used as the confirmatory measure for diagnosis of stroke. We performed a meta-analysis of the three most investigated genes, viz., methylenetetrahydrofolate reductase (MTHFR), apolipoprotein E (ApoE) and angiotensin-converting enzyme (ACE). Statistically significant association with stroke were identified for C677T polymorphism of MTHFR [random effects odds ratio (OR) = 1.47, 95% confidence interval (95% CI) 1.19, 1.82; P = 0.0004] and marginally significant association was detected with allele epsilon 4 of ApoE (random effects OR = 1.47, 95% CI 1.00, 2.15; P = 0.049). The sensitivity analysis (exclusion of studies with controls not in Hardy-Weinberg equilibrium) revealed a significant association of stroke with the MTHFR C677T and ApoE epsilon 4 alleles but showed no association with ACE gene insertion/deletion polymorphism.

Methylenetetrahydrofolate reductase gene polymorphisms are associated with ischemic and hemorrhagic stroke: Dual effect of MTHFR polymorphisms C677T and A1298C

Hyperhomocysteinemia is an independent risk factor for ischemic stroke. The enzyme methylenetetrahydrofolate reductase (MTHFR) plays a critical role in modulating the levels of plasma homocysteine. Two polymorphisms in the MTHFR gene, C677T, A1298C result in reduced enzyme activity. The mechanisms of ischemic and hemorrhagic stroke are not well understood. Although controversial, previous studies have shown evidence of causality of both stroke subtypes in patients with methylenetetrahydrofolate reductase gene polymorphisms. Therefore, we examined whether the C677T and A1298C polymorphisms of MTHFR gene are genetic risk factors for both ischemic and hemorrhagic stroke in a Turkish Caucasian population. In a case-control study, 120 total unrelated stroke patients (92 ischemic stroke, 28 hemorrhagic stroke), and 259 healthy controls were genotyped for C677T and A1298C polymorphisms of the MTHFR gene using a PCR-RFLP based-method. The MTHFR 1298C allele (chi(2)=8.589; P=0.014), C1298C genotype (OR=2.544; P=0.004), and C677C/C1298C compound genotype (OR=3.020; P=0.001) were associated with overall stroke. The MTHFR 1298C allele (chi(2)=11.166; P=0.004), C1298C genotype (OR=2.950; P=0.001), and C677C/C1298C compound genotype (OR=3.463, P=0.0001) were strongly associated with ischemic stroke. Interestingly however, the MTHFR 677T allele (chi(2)=6.033; P=0.049), T677T genotype (OR=3.120; P=0.014), and T677T/A1298A compound genotype (OR=4.211; P=0.002) were associated with hemorrhagic stroke. In conclusion, the C677T and A1298C polymorphisms of the MTHFR gene are genetic risk factors for hamorrhagic and ischemic stroke respectively, independent of other atherothrombotic risk factors.

Dynamic change of coagulation and anticoagulation markers of patients with acute cerebral infarction during intravenous urokinase thrombolysis

BACKGROUND AND OBJECTIVE

The variations of blood coagulation and anticoagulation are of clinical importance in patients with acute cerebral infarction during intravenous urokinase (UK) thrombolysis. Although intravenous heparin is commonly used after thrombolytic therapy, few reports have addressed the relationship between the degree of anticoagulation and clinical outcomes, specifically the effect of thrombolytic agents on hemostasis. In this study, we dynamically monitored the activated partial thromboplastin time (APTT), the prothrombin time (PT), the thrombin time (TT) and the activated partial thromboplasmin time (APTT) in 56 patients with acute cerebral infarction during intravenous urokinase thrombolysis and analysed the relationship among the blood coagulation biomarkers (APTT, PT, TT, AT-III), as well as baseline patient characteristics and clinical outcomes. This allowed us to explore the valuable biomarkers for securing the thrombolysis regimen in clinical practice.

METHODS

The levels of PT, APTT, TT and AT-III in peripheral blood of 56 patients with acute cerebral infarction and 50 normal controls were assayed by ELISA. Dynamic transformation of these markers at the baseline and the time points of the first, second, fourth, eighth, 12th, 24th, 48th, 72nd and 96th hour after intravenous UK thrombolysis was monitored serially. The relationship between the levels of these biomarkers and the clinical effectiveness and safety of urokinase thrombolysis was evaluated.

RESULTS

The levels of PT, APTT, TT and AT-III in patients before intravenous UK thrombolysis were significantly lower than those in age- and sex-matched normal controls (all p<0.05). After treatment with UK, the levels of PT and APTT rose quickly during the first 4 hours (all p< 0.05), and then gradually recovered, reaching baseline at about the 48th hour. The activity of AT-III was slightly increased and showed fluctuations after UK infusion (p< 0.05), however the fluctuated range was not remarkable and lacked specificity.

CONCLUSIONS

Dynamic monitoring of PT, APTT and TT can indicate coagulative and anticoagulative functions of patients with acute cerebral infarction during intravenous urokinase thrombolysis. Monitoring of these markers can be helpful both in regulating the infusion speed and the dosage of UK, as well as increasing the efficacy and safety of UK therapy. However, assay for AT-III might be unnecessary.

The genetics of stroke

PURPOSE OF REVIEW

Ischaemic stroke is a heterogeneous disease caused by different pathogenic mechanisms, of which small artery and large artery stroke are the most common. The identification of the genes involved is unclear. The likely candidate genes associated with stroke are those that are associated with matrix deposition (stromelysin-1, MMP3), inflammation (IL-6), and lipid metabolism (hepatic lipase, APOE, PON1) and clotting (factor V Leiden, fibrinogen).

RECENT FINDINGS

In this review we will only discuss those genes in which there has been a significant contribution to the understanding of stroke since October 2003.

SUMMARY

The published data were reviewed to determine the robustness of these associations and to examine whether there is any evidence of risk modification by factors such as smoking habit, known to be associated with stroke.