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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hyperhomocysteinemia is reported to be an independent risk factor for the development of ischemic stroke. Several studies on genetic variants of methylenetetrahydrofolate reductase (MTHFR, which plays a crucial role in regulation of plasma homocysteine concentration) reported an association between C677T gene polymorphism and stroke in some Asian populations. No study but one detected this association in Caucasians. The purpose of the present case-control study was to find a relationship between MTHFR genotypes and stroke in a Polish population. MTHFR genotypes were determined by PCR in 152 patients with ischemic stroke from northwestern Poland and in 135 consecutive newborns from the same population. The TT genotype and the T allele were significantly more frequent in patients than in the control group (11.8% vs. 4.4%, and 34.5% vs. 21.5%, P<0.01). When males and females were analyzed separately, the differences were statistically significant in both genders. It is concluded that presence of the T allele is a risk factor for ischemic stroke in Polish subjects.
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PMID:C677T polymorphism of the methylenetetrahydrofolate reductase gene and the risk of ischemic stroke in Polish subjects. 1919 85

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.
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PMID:Genetic risk factors for arterial ischemic stroke in children: a possible MTHFR and eNOS gene-gene interplay? 1937 95

Plasma homocysteine concentrations have been associated with the risk of stroke, but its relevance to secondary vascular events and mortality after stroke remains unclear because of inconsistent results from clinical trials. The aim of the present study was to investigate whether plasma homocysteine levels and the MTHFR (methylenetetrahydrofolate reductase) variant C677T contributed to the risk of stroke recurrence and all-cause mortality in a large prospective cohort of stroke patients in a Chinese population. A total of 1823 stroke patients (age, 35-74 years) were recruited during 2000-2001 and prospectively followed-up for a median of 4.5 years. During the follow-up, 347 recurrent strokes and 323 deaths from all-causes were documented. After adjustment for age, gender and other cardiovascular risk factors, a high homocysteine concentration was associated with an increased risk of 1.74-fold for stroke recurrence {RR (relative risk), 1.74 [95% CI (confidence interval), 1.3-2.3]; P<0.0001} and 1.75-fold for all-cause mortality [RR, 1.75 (95% CI, 1.3-2.4); P<0.0001] when highest and lowest categories were compared. Spline regression analyses revealed a threshold level of homocysteine for stroke recurrence. By dichotomizing homocysteine concentrations, the RRs were 1.31 (95% CI, 1.10-1.61; P=0.016) for stroke recurrence and 1.47 (95% CI, 1.15-1.88; P<0.0001) for all-cause mortality in patients with homocysteine levels > or =16 micromol/l relative to those with levels <16 micromol/l. The association of elevated plasma homocysteine concentrations with all-cause mortality was mainly due to an increased risk of cardiovascular deaths. No significant association was found between MTHFR C677T and stroke recurrence or mortality. In conclusion, our findings suggest that elevated homocysteine concentrations can predict the risk of stroke recurrence and mortality in patients with stroke.
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PMID:High plasma homocysteine levels contribute to the risk of stroke recurrence and all-cause mortality in a large prospective stroke population. 1960 27

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.
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PMID:Posterior cerebral artery occlusion after Mycoplasma pneumoniae infection associated with genetic defect of MTHFR C677T. 1961 62

A 23-year-old man using Na-Valproic acid (VPA) was admitted to our clinic due to convulsion. The neurological examination revealed right hemiparesis. From the exitus notes, we learned that his two siblings had died from status epilepticus. Magnetic resonance imaging (MRI), MRI spectroscopy, and diffusion-weighted investigations (DWI) showed acute-subacute ischemic stroke in the left temporo-parieto-occipital region. The patient had an ischemic stroke. Heterozygote methylenetetrahydrofolate reductase (MTHFR) 677C/T polymorphism was determined on genetic examination. The homocysteine (Hcy) level was 18.2 mmol/l (5-15 mmol/l). So VPA treatment was stopped and oxcarbazepine treatment was started. MTHFR 677C/T polymorphism is associated with the risk of vascular diseases due to hyperhomocysteinemia. Heterozygote (MTHFR) 677C/T polymorphism has not been reported to be associated with epilepsy. In patients with heterozygote (MTHFR) 677C/T polymorphism and under long-term use of certain drugs the determination of Hcy plasma levels may be useful to prevent the development of atherothrombotic disease.
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PMID:Na VPA-induced acute ischemic stroke in an epileptic patient with methylenetetrahydrofolate reductase gene polymorphism. 1964 48

The association of factor V-Leiden and methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C mutations with stroke was investigated in 118 patients with stroke and 120 control subjects. MTHFR 677TT (P < .001) and 1298CC (P < .001), but not factor V-Leiden (P = .179), genotypes were associated with stroke. The C677T but not A1298C MTHFR mutation was associated with elevated homocysteine levels in patients and control subjects. In addition to hypertension, the significant predictors for stroke were MTHFR 677CT and TT and A1298CC genotypes, together with hyperhomocysteinemia, indicating a synergistic effect of MTHFR mutations with elevated homocysteine and other risk factors in pathogenesis of stroke.
J Stroke Cerebrovasc Dis
PMID:Case-control Study of methylenetetrahydrofolate reductase mutations and hyperhomocysteinemia and risk of stroke. 1971 29

Genotyping for the methylenetetrahydrofolate reductase gene (MTHFR) has been recommended for part of the evaluation for underlying prothrombotic state in childhood stroke; however, studies are inconclusive regarding the role of this gene and also the role of hyperhomocysteinemia, which is the putative mechanism by which MTHFR polymorphism is related to stroke. The prevalence of MTHFR polymorphism in childhood arterial ischemic stroke and cerebral sinovenous thrombosis was compared with that of a reference population, and prevalence of hyperhomocysteinemia was reviewed. In arterial ischemic stroke, the prevalence of at-risk methylenetetrahydrofolate reductase genotypes was 27%, and in cerebral sinovenous thrombosis it was 13%; the population prevalence was 26%. The odds ratio for at-risk genotype in childhood arterial ischemic stroke was 1.06 (95% confidence interval, 0.22-4.0); in cerebral sinovenous thrombosis, it was 0.42 (95% confidence interval, 0.01-3.6). No tested cases had hyperhomocysteinemia. MTHFR polymorphism and hyperhomocysteinemia were not risk factors in childhood arterial ischemic stroke or cerebral sinovenous thrombosis in the Intermountain West region.
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PMID:Methylenetetrahydrofolate reductase gene polymorphism and childhood stroke. 1974 43

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.
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PMID:The T allele of the 677C>T polymorphism of methylenetetrahydrofolate reductase gene is associated with an increased risk of ischemic stroke in Polish children. 1980 23

Migration to the UK is associated with higher incidence of stroke in African populations. A low folate status has been associated with increased risk of stroke, likely to be mediated through raised plasma homocysteine concentrations. We conducted a cross-sectional study to compare blood folate and homocysteine concentrations in eighty healthy Ghanaian migrants living in London matched by sex, age and occupation to 160 individuals from an urban population in Accra, Ghana. Folate intake was determined using three 24 h recalls. Fasting blood samples were collected for the determination of serum and erythrocyte folate and plasma homocysteine concentrations and the methylenetetrahydrofolate reductase (MTHFR) 677C --> T polymorphism. Reported mean folate intake was 20 % lower in London compared with Accra (P < 0.001). However, serum folate was 44 % higher, erythrocyte folate 30 % higher and plasma homocysteine was 26 % lower in subjects from London compared with those from Accra (P < 0.001). These differences persisted after adjusting for confounders including the MTHFR 677C --> T mutation, which was rare in both populations. Although there were no associations between dietary folate intake and blood folates (P>0.05), folic acid supplement use, which was more prevalent in London than Accra (25 and 10 %, respectively, P = 0.004) was associated with erythrocyte folate in both populations (P < 0.01). The main predictors of plasma homocysteine concentrations were erythrocyte folate and male sex (P < 0.001). Findings from the present study suggest that migration from Ghana to the UK results in improvement of biomarkers of folate status despite the fact that reported dietary intake of folate was apparently lower in subjects from London.
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PMID:Folate status of Ghanaian populations in London and Accra. 1982 17

High blood pressure (BP) and elevated homocysteine are reported as independent risk factors for CVD and stroke in particular. The main genetic determinant of homocysteine concentrations is homozygosity (TT genotype) for the C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene, typically found in approximately 10% of Western populations. The B-vitamins folate, vitamin B12 and vitamin B6 are the main nutritional determinants of homocysteine, with riboflavin more recently identified as a potent modulator specifically in individuals with the TT genotype. Although observational studies have reported associations between homocysteine and BP, B-vitamin intervention studies have shown little or no BP response despite decreases in homocysteine. Such studies, however, have not considered the MTHFR C677T polymorphism, which has been shown to be associated with BP. It has been shown for the first time that riboflavin is an important determinant of BP specifically in individuals with the TT genotype. Research generally suggests that 24 h ambulatory BP monitoring provides a more accurate measure of BP than casual measurements and its use in future studies may also provide important insights into the relationship between the MTHFR polymorphism and BP. Further research is also required to investigate the association between specific B-vitamins and BP in individuals with different MTHFR genotypes in order to confirm whether any genetic predisposition to hypertension is correctable by B-vitamin intervention. The present review will investigate the evidence linking the MTHFR C677T polymorphism to BP and the potential modulating role of B-vitamins.
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PMID:Postgraduate Symposium: The MTHFR C677T polymorphism, B-vitamins and blood pressure. 1995 68


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