Recurrent miscarriage: green-top guideline nº 17

The purpose of this guideline is to provide guidance on the investigation and care of women and people with recurrent miscarriage.Within this document we use the terms woman and women's health. However, it is important to acknowledge that it is not only women for whom it is necessary to access women's health and reproductive services in order to main-tain their gynaecological health and reproductive wellbeing. Gynaecological and obstetric services and delivery of care must therefore be appropriate, inclusive and sensitive to the needs of those individuals whose gender identity does not align with the sex they were assigned at birth. The term cou-ple is used to describe two individuals trying to conceive, recognising that in some instances these individuals may not be in a relationship. While every effort is made to ensure the RCOG uses inclusive language there are instances where we have been unable to adhere to this, for example where original research is being referenced the language within the publication is used for accuracy.

Design and Evaluation of a Method for Testing Polymorphisms of Folate-Related Genes Using the Luminex Liquichip System.

Purpose: The methylene tetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C, and the methionine synthase reductase (MTRR) A66G polymorphisms are the three most common folate metabolism-related loci in the Chinese population. They are associated with numerous birth defects or congenital diseases. To facilitate screening and genetic counseling, we established a method for the simultaneous detection of these three polymorphisms using the Luminex liquid suspension chip and multiple asymmetric polymerase chain reactions (PCRs). Materials and Methods: The three polymorphisms were amplified by multiplex PCR with biotinylated primers, followed by hybridization with six probe-linked magnetic microspheres. The mean fluorescent intensity value in each microsphere was detected by Luminex Magpix for polymorphism detection in 150 samples and confirmed by sequencing. Results: The consistency between the Luminex liquid suspension chip method and sequencing was 100%. Among the 150 randomized samples, the minor allele frequency (MAF) of MTHFR C677T was 0.41, which was the most common variant allele, followed by MTRR A66G (MAF = 0.24), and finally MTHFR A1298C (MAF = 0.19). Conclusion: The Luminex liquid suspension chip method can replace sequencing to analyze the MTHFR C677T, MTRR A1298C, and MTRR A66G loci simultaneously as a rapid, convenient, accurate, and stable method for large-scale testing.

Combined Effect of HPV and Several Gene SNPs in Laryngeal Cancer.

Background and objectives: Laryngeal squamous cell carcinoma (LSCC) is one of the most common head and neck tumors. The molecular mechanism of LSCC remains unclear. The aim of this study was to evaluate the prevalence of Human papillomavirus (HPV) and single nucleotide polymorphisms (SNPs) of TP53, MDM2, MDM4, MTHFR, CASP8, and CCR5 genes in LSCC, and to assess their correlations with patient survival. Materials and Methods: 49 LSCC patients were enrolled in this study. PCR and qRT-PCR were used to detect, identify, and quantify HPV. SNPs were genotyped using PCR and PCR-RFLP. Results: By analyzing the interactions of the SNPs of the genes with clinical parameters, the majority of patients with lymph node status (N1,2) were identified as carriers of MDM2 T/G, CASP8 ins/del, CCR5 wt/wt SNP. Cluster analysis showed that patients with MDM2 T/T SNP survive longer than patients identified as CASP8 ins/ins, MTHFR C/C, and MDM4 A/A variant carriers; meanwhile, LSCC patients with MDM2 T/T polymorphic variant had the best survival. Multivariate analysis showed that HPV-positive patients without metastasis in regional lymph nodes (N0) and harboring CASP8 ins/del variant had the best survival. Meanwhile, HPV-negative patients with identified metastasis in lymph nodes (N1 and N2) and CASP8 ins/del variant had poor survival. Conclusions: This finding suggests patients survival prognosis and tumor behavior are different according HPV status, SNP variants, and clinical characteristics of the LSCC.

Customized MethylC-Capture Sequencing to Evaluate Variation in the Human Sperm DNA Methylome Representative of Altered Folate Metabolism.

BACKGROUND: The sperm DNA methylation landscape is unique and critical for offspring health. If gamete-derived DNA methylation escapes reprograming in early embryos, epigenetic defects in sperm may be transmitted to the next generation. Current techniques to assess sperm DNA methylation show bias toward CpG-dense regions and do not target areas of dynamic methylation, those predicted to be environmentally sensitive and tunable regulatory elements. OBJECTIVES: Our goal was to assess variation in human sperm DNA methylation and design a targeted capture panel to interrogate the human sperm methylome. METHODS: To characterize variation in sperm DNA methylation, we performed whole genome bisulfite sequencing (WGBS) on an equimolar pool of sperm DNA from a wide cross section of 30 men varying in age, fertility status, methylenetetrahydrofolate reductase (MTHFR) genotype, and exposures. With our targeted capture panel, in individual samples, we examined the effect of MTHFR genotype ([Formula: see text] 677CC, [Formula: see text] 677TT), as well as high-dose folic acid supplementation ([Formula: see text], per genotype, before and after supplementation). RESULTS: Through WGBS we discovered nearly 1 million CpGs possessing intermediate methylation levels (20-80%), termed dynamic sperm CpGs. These dynamic CpGs, along with 2 million commonly assessed CpGs, were used to customize a capture panel for targeted interrogation of the human sperm methylome and test its ability to detect effects of altered folate metabolism. As compared with MTHFR 677CC men, those with the 677TT genotype (50% decreased MTHFR activity) had both hyper- and hypomethylation in their sperm. High-dose folic acid supplement treatment exacerbated hypomethylation in MTHFR 677TT men compared with 677CC. In both cases, [Formula: see text] of altered methylation was found in dynamic sperm CpGs, uniquely measured by our assay. DISCUSSION: Our sperm panel allowed the discovery of differential methylation following conditions affecting folate metabolism in novel dynamic sperm CpGs. Improved ability to examine variation in sperm DNA methylation can facilitate comprehensive studies of environment-epigenome interactions. https://doi.org/10.1289/EHP4812.

Rehydration during exercise prevents the increase of homocysteine concentrations.

This study aimed to assess the effect of rehydration during and after acute aerobic submaximal exercise on total homocysteine (tHcy) concentrations and related parameters in physically active adult males. Twenty trained males (29.4 ± 7.9 years old) completed four exercise tests: two without rehydration during exercise (NH1 and NH2), one with rehydration during exercise using water (H1) and one with rehydration during exercise using an isotonic sports drink (H2). After finishing the exercise tests, subjects followed a rehydration protocol for 2 h. Serum tHcy, vitamin B12, folate, creatine and creatinine were analysed before, after and at 2, 6 and 24 h after exercise. Data were analysed with and without correcting for haemoconcentration to assess the changes in tHcy related. The methylenetetrahydrofolate reductase (MTHFR) 677TT genotype was also analysed. THcy (uncorrected by haemoconcentration) increased significantly after exercise (P < 0.05) in the NH1 and NH2 tests [mean increase ± SD: 1.55 ± 0.33 (15.18%) and 1.76 ± 0.25 (17.69%) µmol/L, respectively], while no significant differences were found in the H1 and H2 tests [mean increase: 0.65 (6.29%) and 0.90 (8.69%) µmol/L, respectively]. The increase was partly due to haemoconcentration and partly due to the metabolism underlying acute exercise. THcy concentrations recovered to baseline after 24 h in all tests. In conclusion, adequate rehydration during acute aerobic exercise using either water or a sports drink maintains tHcy concentrations at baseline and for up to 2 h after exercise in physically active male adults and prevents further increases when compared to no rehydration.

Analysis of genetic polymorphism of methylenetetrahydrofolate reductase in a large ethnic Hakka population in southern China.

Methylenetetrahydrofolate reductase (MTHFR) catalyzes conversion of methylene tetrahydrofolate to methylte trahydrofolate. MTHFR C677T polymorphism has been regarded as a risk factor for various vascular diseases. Our study aimed to investigate the distribution frequencies of this polymorphism among Hakka population living in southern China. We retrospectively recruited 5102 unrelated Chinese Hakka subjects. MTHFR C677T polymorphism was tested using the polymerase chain reaction (PCR) and DNA sequencing. A total of 2358 males and 2744 females (aged from 10 years to 101 years) were included in this study. In total, 2835 (55.63%) subjects were homozygous for the C allele (CC), 1939 (38.00%) subjects were heterozygous (CT), and 325 (6.37%) subjects were homozygous for the T allele (TT). The allelic frequency of mutant T was 25.37% with 325 individual homozygous for this defective allele resulting in a frequency of about 6.37% for the TT genotype. According to the study results, the overall frequency of MTHFR C677T genotypes did not differ significantly among the gender and age groups. Our study showed the prevalence of MTHFR C677T polymorphism in a large ethnic Hakka population living in southern China. It would be important implications for the primary prevention of various vascular diseases.

Lethal hepatotoxicity following 5-fluorouracil/cisplatin chemotherapy: a relevant case report.

Some articles have reported severe toxicities induced by cisplatin/5-fluorouracil regimens, nevertheless, severe and lethal liver toxicity has not been previously reported. In this article, we report the case of a 72-year-old woman, who developed fulminant hepatitis, hypoglycemia and hypotension with atrial fibrillation not responding to treatment. After ruling out all other possible causes of hepatitis, the toxicity was more likely attributed to 5-fluorouracil. Genotyping was performed and the patient was found to be a homozygote carrier of the T variant of the MTHFR gene. The patient died two days later. Several factors, including genetic factors, could explain this severe toxicity. The present case discusses the importance of personalized medicine in oncology based on pharmacogenetic analysis of polymorphisms.

Localization of folate metabolic enzymes, methionine synthase and 5,10-methylenetetrahydrofolate reductase in human placenta.

BACKGROUND: Normal fetal development requires adequate folate levels during pregnancy. Although folate metabolic enzymes have important roles in the maintenance of normal fetal development, the location of folate metabolic enzymes, methionine synthase (MTR) and 5,10-methylenetetrahydrofolate reductase (MTHFR), has not been previously examined. METHODS: We investigated the expression of MTR and MTHFR in human term placenta obtained from normal and pregnancy-induced hypertension (PIH) patients. RESULTS: MTR is expressed in the villous syncytiotrophoblast and MTHFR is expressed in the extravillous trophoblast. There was no difference in the quantity and location of these enzymes between control and PIH patients. CONCLUSION: These results suggest that MTR in the villous trophoblast participates in the metabolism of homocysteine by using folate, and MTHFR in the extravillous trophoblast is associated with extratrophoblast invasion.

Comparison of the performance of the Cepheid Xpert HemosIL Factor II and Factor V and the ViennaLab FV-PTH-MTHFR StripAssay kits for molecular thrombophilia profiling.

AIMS: To compare the performance of two assays used for the detection of mutations/polymorphisms in the Factor V, Factor II, and methylenetetrahydrofolate reductase genes among patients referred for the management of a thrombotic event. MATERIALS AND METHODS: We tested 40 different patient samples using two assays, the ViennaLab FV-PTH-MTHFR StripAssay and the Cepheid Xpert HemosIL. RESULTS: The two assays were 100% concordant in their produced results with no samples failing the testing procedures in both. CONCLUSION: This is the first report to evaluate the performance of the ViennaLab FV-PTH-MTHFR StripAssay and the Cepheid Xpert HemosIL. Both assays can be introduced to the operation of molecular diagnostic laboratories to cover the referrals from different disciplines, especially in tertiary care centers with emergency departments.

Association of uricemia with biochemical and dietary factors in human adults with metabolic syndrome genotyped to C677T polymorphismin the methylenetetrahydrofolate reductase gene / Asociación de la uricemia con factores bioquímicos y dietéticos en humanos adultos con síndrome metabólico genotipados para el polimorfismo C677T en el gen metilenotetrahidrofolato reductasa

It is suggested that hyperuricemia is a marker of cardiovascular risk in human adults with metabolic syndrome(MS). The C677T polymorphism in the gene encoding the enzyme methylenetetrahydrofolate reductase (MTHFR) is associated with hyperuricemia. Data on factors associated with uricemia in human adults with MS genotyped for this polymorphism are lacking. We aimed to investigate the factors associated with uricemia in human adults with MSgenotyped for the C677T polymorphism in the MTHFR gene. Cross-sectional study was conducted with 63 human adults (24 men and 39 women) with MS. Body weight, body mass index, waist circumference, body fat, glycemia, lipidprofile, uricemia, insulinemia, homocysteinemia, plasmafolate, erythrocyte folate, blood pressure, smoking, diuretics use, usual dietary alcohol and protein intakes, and the presence of the C677T polymorphism in the MTHFR gene were assessed. Hyperuricemia was observed in 16 (25.4%)human adults (10 men and 6 women). In the group, 33% (n= 21) showed the C677T polymorphism, being 19 heterozygous and 2 mutant homozygous. A significant association between hyperuricemia and C677T polymorphism was not verified. Uricemia was positively associated with homocysteinemia (r = 0.43, p < 0.05), triglyceridemia (r = 0.41,p<0.05), serum concentrations of very-low-density lipoprotein(r = 0.27, p< 0.05) and the habitual alcohol intake (r =0.37, p < 0.05). However, only homocysteinemia, triglyceridemia, and habitual alcohol intake remained in the final model of linear regression. In human adults with MS genotyped for the C677T polymorphism in the MTHFR gene, uricemia was positively associated with homocysteinemia, triglyceridemia and the habitual alcohol intake (AU)

Sugiérese que la hiperuricema sea un factor de riesgo cardiovascular en humanos adultos con síndrome metabólico(SM) El polimorfismo C677T en el gen metilenotetrahidrofolato reductasa (MTHFR) ha sido asociado com la hiperuricemia. Datos sobre los factores asociados con la uricemia en humanos adultos con SM genotipados para el polimorfismo C677T en el gen MTHFR son inexistentes. Se objetivó investigar los factores asociados con lauricemia en individuos con SM genotipados para el polimorfismo C677T. Se ha realizado un estudio transversal con 63 humanos adultos (24 hombres y 39 mujeres). Fueron evaluados peso, altura, índice de masa corporal, circunferencia de la cintura, grasa corporal total, glucemia, uricemia, insulinemia, homocisteinemia, folato plasmático, folato en los eritrocitos, presión arterial, tabaquismo,uso de diuréticos, ingesta habitual de proteínas dietéticas y de alcohol y la presencia del polimorfismo C677T. No fue encontrado asociación significativa entre el polimorfismo C677T y la uricemia. Fue verificado que un 25,4% (n = 16) do los individuos presentaban hiperuricemia (10 hombres y 6 mujeres). Se verificó que un 33%(n = 21) de los individuos presentaron el polimorfismo C677T (19 heterocigotos y 2 homocigotos polimórficos). La uricemia se asoció con los niveles de homocisteina (r =0,43, p < 0,05), trigicéridos (r = 0,41, p < 0,05) y de lipoproteínas de muy baja densidad (r = 0.27, p < 0,05) y conla ingesta de alcohol (r = 0,37, p < 0,05). Sin embargo, sólo la homocisteinemia, la trigliceridemia y la ingesta habitual de alcohol permanecerán en el modelo final de regresión lineal. En los humanos adultos con SM genotipados para el polimorfismo C677T en el gen MTHFR, la uricemia se asoció positivamente con los niveles de homocisteína y triglicéridos y con la ingesta habitual de alcohol (AU)

Asociación entre hiperhomocisteinemia y esteatosis hepática en pacientes con hepatitis crónica C / Association of hyperhomocysteinemia with liver steatosis in patients with chronic hepatitis C

Fundamento y objetivo: La esteatosis hepática en la hepatitis crónica C (HCC) se relaciona con factores virales, metabólicos y posiblemente genéticos. El objetivo de este estudio es conocer si la hiperhomocisteinemia y el polimorfismo de la metilentetrahidrofolato reductasa (MTHFR)-C677T se asocian a esteatosis hepática en pacientes no alcohólicos con HCC. Pacientes y método: Se estudiaron 54 pacientes consecutivos diagnosticados de HCC mediante biopsia, con consumo de alcohol menor de 40g/semana, y sin otras causas de enfermedad hepática. Todas las variables se obtuvieron al tiempo de la biopsia. En 128 sujetos sanos, con edad y sexo similares a los pacientes, también se determinó el polimorfismo de la MTHFR-C677T. Resultados: Se encontró esteatosis hepática en 33 pacientes (61%), siendo en 30 de grado leve. En los pacientes con esteatosis existía una prevalencia más elevada de hiperhomocisteinemia (61% frente al 24%, p=0,008) y el sobrepeso tendía a ser más prevalente (61% frente al 33%, p=0,05). Todos los pacientes con genotipo 3 del virus C tenían esteatosis. La carga viral, actividad inflamatoria y fibrosis hepática no fueron diferentes en los pacientes con y sin esteatosis. El polimorfismo de la MTHFR-C677T fue similar en controles y casos, y en los casos con y sin esteatosis. La regresión logística múltiple mostró que la hiperhomocisteinemia se asociaba a esteatosis hepática tras ajustar por edad y sexo (odds ratio [OR] 3,94, intervalo de confianza del 95% [IC 95%] 1,09-14,29) y por sobrepeso (OR 4,43, IC 95% 1,27-15,51). Conclusiones: En pacientes no alcohólicos con HCC, la esteatosis hepática de grado leve es frecuente y se asocia a hiperhomocisteinemia. No se comprueba asociación de la esteatosis con el polimorfismo de la MTHFR-C677T (AU)

Background and objectives: Liver steatosis in chronic hepatitis C (CHC) is related to viral and metabolic factors and likely to genetic factors. The aim of this study was to know if hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR)-C677T polymorphisms are associated with liver steatosis in nonalcoholic patients with CHC.Patients and method: In 54 consecutive patients with CHC, alcohol consumption less than 40g/week, and no other causes of liver disease, a liver biopsy was performed. All variables were obtained at the time of biopsy. MTHFR-C677T was also performed in 128 healthy subjects, with age and gender similar to the patients. Results: Liver steatosis was found in 33 patients (61%), 30 of them having a mild degree. Hyperhomocysteinemia was more prevalent in patients with steatosis (61% vs 24%; p=0.008) and overweight tended to be more prevalent in the same patients (61% vs 33%; p=0.05). All patients with virus C genotype 3 had steatosis. Viral load, liver inflammatory and fibrosis score were not different in patients with and without steatosis. MTHFR-C677T polymorphism was similar in controls and cases and in cases with and without steatosis. A multiple logistic regression showed that hyperhomocysteinemia was associated with liver steatosis after adjustment for age and sex (OR: 3.94; 95% CI: 1.09-14.29), and adjustment for overweight (OR: 4.43; 95% CI: 1.27-15.51). Conclusions: In nonalcoholic patients with CHC mild liver steatosis is frequent, and is associated with hyperhomocysteinemia. An association between steatosis and MTHFR-C677T polymorphism was not found (AU)

Long-living growth hormone receptor knockout mice: potential mechanisms of altered stress resistance.

Endocrine mutant mice have proven invaluable toward the quest to uncover mechanisms underlying longevity. Growth hormone (GH) and insulin-like growth factor (IGF) have been shown to be key players in physiological systems that contribute to aging processes including glucose metabolism, body composition and cellular protection. Examination of these mutant mice across several laboratories has revealed that differences exist in both the direction and magnitude of change, differences that may result in variation in life span. Growth hormone receptor knockout mice lack a functional GH receptor, therefore GH signaling is absent. These mice have been shown to lack the heightened oxidative defense mechanisms observed in other GH mutants yet live significantly longer than wild type mice. In this study, glutathione (GSH) and methionine (MET) metabolism was examined to determine the extent of variation in this mutant in comparison to the Ames dwarf, a mouse that exhibits delayed aging and life span extension of nearly 70%. Components of GSH and MET were altered in GHR KO compared to wild type controls. The results of these experiments suggest that these pathways may be partially responsible for differences observed in stress resistance and the capacity to respond to stressors, that in the long term, affect health and life span.

Relación entre los polimorfismos de la metilen-tetrahidrofolato-reductasa y los niveles de homocisteína en mujeres con pérdida gestacional recurrente: perspectiva desde la nutrigenética / Relationship between methylenetetrahydrofolate reductase polymorphism and homocysteine levels in women with recurrent pregnancy loss: a nutrigenetic perspective

El objetivo de este estudio fue evaluar si existe diferencia en la proporción de los polimorfismos de la metilen tetrahidrofolato reductasa (MTHFR) C677T y en los niveles de homocisteína, entre una población de mujeres con pérdida gestacional recurrente y un grupo control. Se incluyeron 93 pacientes con diagnóstico de tres o más pérdidas gestacionales y 206 mujeres sanas con dos o más hijos. Previa aceptación del consentimiento informado, a cada mujer se le tomó una muestra de sangre periférica tanto para la genotipificación de los polimorfismos de la MTHFR como para la medición de homocisteína en plasma. Las portadoras de la condición homocigota TT para el polimorfismo de la MTHFR 677T fueron 12,9% (12/93) en el grupo de pacientes y 14,6% (30/206) en el grupo control; un 46,2% (43/93) y 40% (83/206) en el grupo de pacientes y de controles respectivamente, fueron heterocigotos CT para el gen de la MTHFR. Los niveles promedio de homocisteína fueron 7,2 μmol/ml para las pacientes y 7,7 μmol/ml para los controles. No se encontró relación entre los polimorfismos del gen de la MTHFR y el aumento en los niveles de homocisteína, ni de éstos con la PGR. Desde la perspectiva de la nutrigenética, sugerimos que para estudiar la relación entre los polimorfismos de la MTHFR con determinada enfermedad, se tengan en cuenta los niveles de folatos, vitaminas B6 y B12 que intervienen en el ciclo de los tetrahidrofolatos con el fin de intentar establecer una relación más directa entre el genotipo, el nivel del metabolito y las manifestaciones clínicas. En este mismo sentido recomendamos el consumo de ácido fólico en las mujeres que estén buscando embarazo dado la alta frecuencia de heterocigotos y homocigotos para la mutación C677T de la MTHFR en nuestra población (AU)

The objective of this study was to evaluate if there is any difference in the proportion of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms and the homocysteine levels in a group of women with recurrent pregnancy loss (RPL) and a control group. Ninety-three patients with diagnosis of three or more gestational losses and 206 healthy women with two or more children, were included. After acceptance of informed consent, samples of peripheral blood were taken to determine the genetic polymorphisms of MTHFR C677T and the plasmatic levels of homocysteine. The carriers of the homozygous mutation TT of MTHFR 677T polymorphism were 12.9% (12 of 93) in the group of patients and 14.6% (30 of 206) in the control group; 46.2% (43 of 93) and 40% (83 of 206) in the group of patients and controls respectively, were heterozygous CT for MTHFR gene. The levels of homocysteine were 7.2 μmol/ml in the group of patients and 7.7 mmol/l in controls. There was no relationship between MTHFR gene polymorphisms and the increase of homocysteine levels, nor of these one with RPL. From the nutrigenetics perspective we suggest that studies related to MTHFR polymorphisms and the risk of disease include the levels of folate and B6 and B12 vitamins participating in the tetrahydrofolate cycle for trying to establish a direct relation among the genotype, the level of metabolite and the clinical manifestations. In this regard, we recommend the administration of folic acid in women in search of pregnancy due to the high frequency of heterozygous and homozygous for MTHFR C677T mutation in our population (AU)

Primer-engineered multiplex PCR-RFLP for detection of MTHFR C677T, prothrombin G20210A and factor V Leiden mutations.

Single-nucleotide polymorphisms in the genes that code for coagulation factors V (factor V Leiden) and II (prothrombin, G20210A), as well as the methylenetetrahydrofolate reductase (MTHFR, C677T) gene, have been implicated in the majority of cases of hereditary thrombophilia. We have developed a multiplex PCR-RFLP assay based on MnlI endonuclease digestion for the simultaneous detection of mutations in the FV, FII, and MTHFR genes. Digested amplification products were analyzed by gel electrophoresis in a single gel lane and visualized by ethidium bromide. This approach is a rapid and convenient method, hence economic, that alternate to others described for the detection of FVL, G20210A and C677T mutations.

Modulation of DNA methyltransferase profile by methyl donor starvation followed by gamma irradiation.

DNA methylation is an important epigenetic mechanism of transcriptional control, which plays an essential role in maintaining cellular function. Role of one-carbon transfer agents/methyl donors namely folate, choline and methionine in DNA methylation has been the subject of extensive investigation. The methylation pattern of DNA is established during embryogenesis by DNA methyltransferase 3 (dnmt3) and is subsequently maintained by maintenance methylation activity of the enzyme DNA methyltransferase 1 (dnmt1). Ionizing radiation is known to extensively damage the DNA. Sufficient dietary availability of methyl donors is known to contribute towards one-carbon transfer mediated repair of damaged DNA where folate is involved in nucleotide base synthesis. In the present study, modification in activities of dnmt1 and dnmt3 by methyl donor starvation followed by gamma-irradiation was observed. Assays were based on the catalytic transfer of (3)H-methyl groups from S-adenosyl-L: -methionine to a DNA substrate. Experiments showed a dose and methyl donors starvation dependent attenuation in dnmt1 activity. Attenuation of dnmt1 activity was most significant for diet deprived of all the three-methyl donors. No significant change in nuclear or cytoplasmic dnmt3 activity was observed when either or all the three possible source of dietary methyl group supply were removed. Ionizing radiation and methyl donor deficiency were observed to act synergistically towards inhibiting dnmt1 activity. Present results suggested possibility of interaction among folate, methionine and choline deficiency to potentiate symptoms of ionizing radiation stress. These enzymatic modifications might contribute to altered DNA methylation after chronic feeding of methyl donor free diets followed by gamma irradiation. These results suggested that dietary availability of methyl donors and gamma-radiation stress might significantly alter the dnmt1 profile.

Evaluation of factor V Leiden, prothrombin and methylenetetrahydrofolate reductase gene mutations in patients with severe pregnancy complications in northern Finland.

BACKGROUND: Thrombosis in placenta may lead to severe pregnancy complications. Most important inherited thrombophilias are factor V Leiden mutation, prothrombin mutation, and methylenetetrahydrofolate reductase mutation. The aim of our research was to evaluate the prevalence of inherited thrombophilias in severe pregnancy complications and in normal pregnancies. MATERIAL AND METHODS: The study subjects with severe preeclampsia, intrauterine growth restriction, placental abruption or fetal death were collected during the period 1999-2004 from Oulu University Hospital. We also collected during the same period voluntary parturients with normal pregnancy outcome as the control group. FVL, FII, and MTHFR gene mutations of the patients and controls were analyzed. RESULTS: We found a significant difference in the prevalence of FVL mutation between the groups. There were 9.5% FVL mutations in the study group compared to 1.8% in the control group; the observed difference between prevalences was 7.7% (95% CI 2.0-13.4). No statistical difference was found in the FII or MTHFR mutations between the groups. All FV and FII mutations were heterozygous and all the MTHFR mutations homozygous. CONCLUSION: Women with thrombophilia have a risk for severe pregnancy complications. Randomized controlled trials are needed to assess the influence of low-molecular-weight heparin in pregnant women with thrombophilia.

Thrombophilia in infancy: factor V Leiden and MTHFR or factor II double heterozygocity as a risk factor.

Thrombophilic risk factors are associated with thromboembolism in children but data in infants and neonates are not well established. The authors report a series of 9 infants with thrombotic events and the associated genetic risk factors. The clinical and laboratory records of newborns and infants with a history of thrombotic events were summarized, while patients with underlying diseases were excluded. The frequency of the genetic mutations was compared to a control group of 80 children from the same ethnic origin. In 6 patients a cerebrovascular accident was diagnosed and in 3 newborns, CT scan could diagnose antenatal brain infarct. In another 2 patients deep-vein thrombosis associated with femoral catheterization was diagnosed. Seven infants were factor V Leiden heterozygous and another one homozygous. Methylenetetrahydrofolate reductase genotype was found in 5 infants. Five cases were found to be double heterozygous for those two mutations, and another one double heterozygous for FVL and factor II. The results of this small series of patients indicate that cerebrovascular accident is the major thrombotic event in infants and the combination of more than one prothrombotic factors may be the cause of those events. The correct management, including anticoagulant therapy, is still under discussion and waiting for larger series and long-term follow-up results until accurate recommendations can be made.