MTHFR Mutation (mthfr + mutation)

Distribution by Scientific Domains

Selected Abstracts

The MTHFR C677T polymorphism confers a high risk for stroke in both homozygous and heterozygous T allele carriers with Type 2 diabetes

M. P. Hermans
Abstract Objective Individuals with Type 2 diabetes are at increased risk of stroke. Plasma homocysteine (tHcy) is an independent risk factor for cardiovascular (CV) disease. The methylene,tetrahydrofolate reductase (MTHFR) gene polymorphism (thermolabile variant C677T) is associated with CV risk, partly as a result of increased Hcy, especially in homozygous subjects. Aim To relate the occurrence of the MTHFR polymorphism with stroke prevalence by examining allelic frequency and genotype distribution in 165 subjects with Type 2 diabetes studied for the presence of thermolabile C677T MTHFR mutation. Results Mean age was 67.7 years, and tHcy 18.2 µmol/l. T allele frequency was 38.5%. MTHFR genotypes were: normal (CC) 40%; heterozygous (CT) 43%; homozygous (TT) 17%. Serum levels of folic acid and B12 vitamin were within normal limits. Stroke prevalence was 14%. Sixty-four per cent of stroke-free subjects had the normal C allele vs. 46% in stroke subjects. The frequencies of genotypes (CC-CT-TT) were (%): 44-41-15 in stroke-free vs. 17-57-26 in stroke patients. Coronary (CAD) and peripheral artery disease (PAD) were common in all groups, with no differences according to genotypes. Stroke prevalence was markedly higher in genotypes CT and TT (18 and 21%) compared with CC (6%). Mean tHcy levels were higher in TT subjects. Conclusion The allelic frequency of C677T MTHFR mutation in Type 2 diabetes subjects with stroke is markedly different from that of subjects without stroke. Genotypic characteristics suggest that C677T MTHFR mutation confers a higher risk for stroke to both homozygous and heterozygous T allele carriers that cannot be ascribed solely to raised tHcy and/or lower folate status in CT subjects, nor to phenotypic expression of conventional risk factors for stroke. The impact of the MTHFR polymorphism on stroke may result from T allele-linked deleterious effects, or C allele-linked protection. Confirmatory studies are warranted, as this cohort was not randomly selected, and a type 1 error cannot be ruled out. [source]

Livedoid vasculopathy and hypercoagulability in a patient with primary Sjögren's syndrome

Raquel Cardoso MD
Background, A 31-year-old woman presented with a 5-year history of painful ulcerations, palpable purpura, porcelain-white atrophic scars of the malleolar region and dorsal aspect of the feet, livedo reticularis on the limbs, arthralgia, xerophthalmia, and xerostomia. Methods, Skin biopsy revealed vessel wall hyalinization and thrombosis of the microvasculature with a very scarce dermal inflammatory infiltrate. Biopsy of the oral mucosa showed mononuclear infiltration of an intralobular duct of a salivary gland. Results, Laboratory studies, including autoantibodies and inflammation markers, were normal, except for a positive rheumatoid factor. Coagulation screening revealed C677T methylenetetrahydrofolate reductase (MTHFR) mutation, with a normal serum homocysteine. The patient was treated with oral methylprednisolone (32 mg/day with progressive reduction) and enoxaparin (20 mg/day subcutaneously), with complete ulcer healing within 4 months. Conclusion, Livedoid vasculitis or vasculopathy has not been referred to previously in association with Sjögren's syndrome, but may be associated with other autoimmune disorders and anomalies of coagulation, namely factor V Leiden mutation, protein C deficiency, and MTHFR mutation, associated or not with hyperhomocysteinemia, a condition that seems to confer an increased risk of recurrent arterial and venous thrombosis. We stress the importance of anticoagulant therapy for ulcer healing and for the prevention of other thrombotic events. [source]

Double inherited thrombophilias and adverse pregnancy outcomes: Fashion or science?

Giovanni Larciprete
Abstract Aim:, To determine to what extent double inherited thrombophilias are associated with adverse obstetric complications correlated with fetoplacental insufficiency, such as preeclampsia, hemolytic anemia elevated liver enzymes and low platelet count (HELLP) syndrome, gestational hypertension, fetal growth restriction (FGR), intrauterine death (ID), abruptio placentae and disseminated intravascular coagulopathy. Methods:, Pregnant women coming to delivery were retrospectively divided into two groups: group A (controls) and group B (cases). Patients belonging to group B had one of the following: severe preeclampsia, HELLP syndrome, gestational hypertension, FGR, intrauterine death, abruptio placentae of disseminated intravascular coagulopathy. We detected methylenetetrahydrofolate reductase (MTHFR) A1298C, MTHFR C677T, factor V Leiden, PAI-1, mutant prothrombin G20210A, plasma homocysteine, antithrombin III, protein S and activated protein C resistance. Normal pregnant women or pregnant women with double defects were enrolled in this study. Results:, The combination of MTHFR C677T mutation with PAI-1 (5G/5G) mutation was significantly linked with the occurrence of ID. HELLP syndrome was significantly related to the simultaneous presence of factor VIII and X mutations. The combination of MTHFR C677T with factor VIII mutation and the combination of factor II and V mutations were significantly related to the occurrence of abruptio placentae. We found an association between double isoforms MTHFR mutation and FGR. Conclusion:, It seems that some thrombophilias and a combination of thrombophilic factors carry a greater risk than others for a given adverse outcome. Further studies are needed to check the link between thrombophilic gene mutations and adverse pregnancy outcomes, such as recurrent miscarriages and deep venous thrombosis. [source]

The folate metabolic enzyme ALDH1L1 is restricted to the midline of the early CNS, suggesting a role in human neural tube defects

Todd E. Anthony
Abstract Folate supplementation prevents up to 70% of human neural tube defects (NTDs), although the precise cellular and metabolic sites of action remain undefined. One possibility is that folate modulates the function of metabolic enzymes expressed in cellular populations involved in neural tube closure. Here we show that the folate metabolic enzyme ALDH1L1 is cell-specifically expressed in PAX3-negative radial glia at the midline of the neural tube during early murine embryogenesis. Midline restriction is not a general property of this branch of folate metabolism, as MTHFD1 displays broad and apparently ubiquitous expression throughout the neural tube. Consistent with previous work showing antiproliferative effects in vitro, ALDH1L1 upregulation during central nervous system (CNS) development correlates with reduced proliferation and most midline ALDH1L1+ cells are quiescent. These data provide the first evidence for localized differences in folate metabolism within the early neural tube and suggest that folate might modulate proliferation via effects on midline Aldh1l1+ cells. To begin addressing its role in neurulation, we analyzed a microdeletion mouse strain lacking Aldh1l1 and observed neither increased failure of neural tube closure nor detectable proliferation defects. Although these results indicate that loss-of-function Aldh1l1 mutations do not impair these processes in mice, the specific midline expression of ALDH1L1 and its ability to dominantly suppress proliferation in a folate responsive manner may suggest that mutations contributing to disease are gain-of-function, rather than loss-of-function. Moreover, a role for loss-of-function mutations in human NTDs remains possible, as Mthfr null mice do not develop NTDs even though MTHFR mutations increase human NTD risk. J. Comp. Neurol. 500:368,383, 2007. © 2006 Wiley-Liss, Inc. [source]