Zika virus serological diagnosis: commercial tests and monoclonal antibodies as tools.

Zika virus (ZIKV), an emerging arthropod-borne virus (arbovirus) of the Flaviviridae family, is a current issue worldwide, particularly because of the congenital and neurological syndromes associated with infection by this virus. As the initial clinical symptoms of all diseases caused by this group are very similar, clinical diagnosis is difficult. Furthermore, laboratory diagnostic efforts have failed to identify specific and accurate tests for each virus of the Flaviviridae family due to the cross-reactivity of these viruses in serum samples. This situation has resulted in underreporting of the diseases caused by flaviviruses. However, many companies developed commercial diagnostic tests after the recent ZIKV outbreak. Moreover, health regulatory agencies have approved different commercial tests to extend the monitoring of ZIKV infections. Considering that a specific and sensitive diagnostic method for estimating risk and evaluating ZIKV propagation is still needed, this review aims to provide an update of the main commercially approved serological diagnostics test by the US Food and Drug Administration (FDA) and Brazilian National Health Surveillance Agency (ANVISA). Additionally, we present the technologies used for monoclonal antibody production as a tool for the development of diagnostic tests and applications of these antibodies in detecting ZIKV infections worldwide.

Zika virus serological diagnosis: commercial tests and monoclonal antibodies as tools

Zika virus (ZIKV), an emerging arthropod-borne virus (arbovirus) of the Flaviviridae family, is a current issue worldwide, particularly because of the congenital and neurological syndromes associated with infection by this virus. As the initial clinical symptoms of all diseases caused by this group are very similar, clinical diagnosis is difficult. Furthermore, laboratory diagnostic efforts have failed to identify specific and accurate tests for each virus of the Flaviviridae family due to the cross-reactivity of these viruses in serum samples. This situation has resulted in underreporting of the diseases caused by flaviviruses. However, many companies developed commercial diagnostic tests after the recent ZIKV outbreak. Moreover, health regulatory agencies have approved different commercial tests to extend the monitoring of ZIKV infections. Considering that a specific and sensitive diagnostic method for estimating risk and evaluating ZIKV propagation is still needed, this review aims to provide an update of the main commercially approved serological diagnostics test by the US Food and Drug Administration (FDA) and Brazilian National Health Surveillance Agency (ANVISA). Additionally, we present the technologies used for monoclonal antibody production as a tool for the development of diagnostic tests and applications of these antibodies in detecting ZIKV infections worldwide.(AU)

Expression of hsa-miR-9 and MYC Copy Number Variation in Hereditary Diffuse Gastric Cancer.

BACKGROUND/AIM: Approximately, 15-50% of families affected by hereditary diffuse gastric cancer (HDGC) exhibit CDH1 germline mutations. CDH1 gene encodes E-cadherin, protein essential to the cell-cell contact of gastric epithelium. Studies have shown that hsa-miR-9 participates in this protein downregulation. Moreover, MYC is responsible for the transcription of hsa-miR-9-3. In the present study, hsa-miR-9 expression and MYC copy number variation were investigated to elucidate the hsa-miR-9 role in HDGC. PATIENTS AND METHODS: Tumor samples were obtained from nine individuals with HDGC history belonging to four Brazilian families. Then, relative quantification of hsa-miR-9 expression and MYC gene copy number variation analysis were performed by real-time PCR. RESULTS: In all the samples, an overexpression of hsa-miR-9 and an increased MYC copy number (≥3 copies) were observed. CONCLUSION: hsa-miR-9 acts as an oncomiR in HDGC. In addition, we suggest that hsa-miR-9 acts as second event in individuals with HDGC carrying CDH1 gene germinline mutations.

Role of miRNAs and their potential to be useful as diagnostic and prognostic biomarkers in gastric cancer.

Alterations in epigenetic control of gene expression play an important role in many diseases, including gastric cancer. Many studies have identified a large number of upregulated oncogenic miRNAs and downregulated tumour-suppressor miRNAs in this type of cancer. In this review, we provide an overview of the role of miRNAs, pointing to their potential to be useful as diagnostic and/or prognostic biomarkers in gastric cancer. Moreover, we discuss the influence of polymorphisms and epigenetic modifications on miRNA activity.

The Emerging Role of miRNAs and Their Clinical Implication in Biliary Tract Cancer.

Biliary tract cancers are aggressive malignancies that include gallbladder cancer and tumors of intra- and extrahepatic ducts and have a poor prognosis. Surgical resection remains the main curative therapy. Nevertheless, numerous patients experience recurrence even after radical surgery. This scenario drives the research to identify biliary tract cancer biomarkers despite the limited progress that has been made. Recently, a large number of studies have demonstrated that deregulated expression of microRNAs is closely associated with cancer development and progression. In this review, we highlight the role and importance of microRNAs in biliary tract cancers with an emphasis on utilizing circulating microRNAs as potential biomarkers. Additionally, we report several single-nucleotide polymorphisms in microRNA genes that are associated with the susceptibility of biliary tract tumors.

Análise do potencial antioxidante do consumo oral da farinha produzida com micélio de Agaricus brasiliensis em hamsters hipercolesterolêmicos / The antioxidant potential of oral intake of flour produced from Agaricus brasiliensis mycelium in hamsters with hypercholesterolemia

O sistema de defesa antioxidante inibe ou reduz os danos causados às células pelas espécies reativas de oxigênio. Alguns compostos antioxidantes presentes na dieta auxiliam na defesa antioxidante do plasma. O potencial antioxidante do consumo oral de farinha produzida com micélio de Agaricus brasiliensis fermentado sobre grãos de trigo foi analisado nos plasmas de hamsters Golden Syrian machos hipercolesterolêmicos, que foram divididos em quatro grupos: P(dieta padrão), H (dieta hipercolesterolêmica padrão), C (dieta padrão + 10 % de farinha de trigo contendo micélio de A. brasiliensis), e HC (dieta hipercolesterolêmica padrão + 10 % de farinha de trigo contendo micélio deA. brasiliensis). Os animais foram alimentados durante 40 dias e depois sacrificados para coletar materiais biológicos.A análise da capacidade antioxidante mostrou que a dieta do grupo C induziu maior aumento significativo da concentração de antioxidantes no plasma (0,39 mg.mL-1, expresso em ácido ascórbico). O grupo HC apresentou maiorcapacidade antioxidante do que grupo H (p < 0,05), pois inibiu 20,2 % do branqueamento da crocina. O grupo H inibiu10,4 %, porém o grupo HC demonstrou capacidade antioxidante semelhante ao do grupo P (16,64 %). O consumo da farinha de trigo contendo micélio de A. brasiliensis estimulou a proteção antioxidante no plasma dos animais...

Association between sex hormone-binding globulin (SHBG) and metabolic syndrome among men.

CONTEXT AND OBJECTIVE: Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG), sex hormones and metabolic syndrome among men. DESIGN AND SETTING: Retrospective analysis on data from the study "Endogenous oestradiol but not testosterone is related to coronary artery disease in men", conducted in a hospital in São Paulo. METHODS: Men (aged 40-70) who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII). Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein), triglycerides, albumin, SHBG, estradiol and total testosterone (TT). The levels of LDL-cholesterol (low density lipoprotein) were calculated using Friedewald's formula and free testosterone (FT) and bioavailable testosterone (BT) using Vermeulen's formula. RESULTS: 141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT. CONCLUSION: Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association.

Association between sex hormone-binding globulin (SHBG) and metabolic syndrome among men / Associação entre globulina de ligação a hormônio sexual (SHBG) e síndrome metabólica em homens

CONTEXT AND OBJECTIVE: Metabolic syndrome consists of a set of factors that imply increased risk of cardiovascular diseases. The objective here was to evaluate the association between sex hormone-binding globulin (SHBG), sex hormones and metabolic syndrome among men. DESIGN AND SETTING: Retrospective analysis on data from the study "Endogenous oestradiol but not testosterone is related to coronary artery disease in men", conducted in a hospital in São Paulo. METHODS: Men (aged 40-70) who underwent coronary angiography were selected. The age, weight, height, waist circumference, body mass index and prevalence of dyslipidemia, hypertension and diabetes of each patient were registered. Metabolic syndrome was defined in accordance with the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation and Treatment of High Blood Cholesterol in Adults (NCEP-ATPIII). Serum samples were collected to assess the levels of glucose, total cholesterol, HDL-cholesterol (high density lipoprotein), triglycerides, albumin, SHBG, estradiol and total testosterone (TT). The levels of LDL-cholesterol (low density lipoprotein) were calculated using Friedewald's formula and free testosterone (FT) and bioavailable testosterone (BT) using Vermeulen's formula. RESULTS: 141 patients were enrolled in the study. The prevalence of metabolic syndrome was significantly higher in the first SHBG tercile than in the second and third terciles. A statistically significant positive association between the SHBG and TT values was observed, but no such association was seen between SHBG, BT and FT. CONCLUSION: Low serum levels of SHBG are associated with higher prevalence of metabolic syndrome among male patients, but further studies are required to confirm this association. .

CONTEXTO E OBJETIVO: A síndrome metabólica (SM) consiste em um conjunto de fatores que implicam risco elevado para doenças cardiovasculares. O objetivo foi avaliar a associação entre a globulina ligadora de esteroides sexuais (SHBG), hormônios sexuais e a SM em homens. TIPO DE ESTUDO E LOCAL: Análise retrospectiva de dados do estudo "Estradiol mas não testosterona se correlaciona com doença arterial coronariana em homens", conduzido em um hospital em São Paulo. MÉTODOS: Foram selecionados pacientes do sexo masculino com idade entre 40 e 70 anos, submetidos a angiografia coronária. A idade, a prevalência de dislipidemia, hipertensão e diabetes, o peso, a altura, cintura e o índice de massa corpórea de cada paciente foram coletados. A definição de SM seguiu os critérios do NCEP-ATPIII. Amostras séricas foram coletadas para análises da glicose, colesterol total, colesterol-HDL (high density lipoprotein), triglicerídeos, albumina, SHBG, estradiol e testosterona total (TT). O colesterol-LDL (low density lipoprotein) foi calculado pela fórmula de Friedewald e as testosteronas livre (TL) e biodisponível (TB) pela fórmula de Vermeulen. RESULTADOS: Entraram no estudo 141 pacientes. A prevalência de SM foi significativamente maior no primeiro tercil de SHBG em comparação ao segundo e terceiro tercis. Foi verificada uma associação positiva e significativa ente os valores de SHBG e TT, porém essa associação não foi verificada entre SHBG e TB e TL. CONCLUSÃO: Baixos níveis séricos de SHBG estiveram associados com alta prevalência da SM em pacientes do sexo masculino. Faz-se necessário que estudos avaliem essa associação. .

Resistência adesiva após colagem e recolagem de bráquetes: um estudo in vitro / Bond strength after bonding and rebonding of brackets: an in vitro study

A busca por um material adesivo para recolagem de bráquetes com adesão adequada desperta interesse ao ortodontista. A resina fotopolimerizável ReBond® foi introduzida na Ortodontia com esta finalidade. Objetivos: Avaliar e comparar o desempenho in vitro do ReBond® com a resina Transbond XT® na recolagem de bráquetes metálicos. Materiais e Métodos: Noventa incisivos inferiores bovinos foram divididos em 3 grupos (n=30): Grupo I: bráquetes colados com resina Transbond® e colagem de novos bráquetes com resina Transbond®; Grupo II: bráquetes colados com resina Transbond® e recolados com resina Rebond®; Grupo III: bráquetes colados e recolados com resina Transbond®. Os corpos de prova foram submetidos ao teste de cisalhamento na máquina de ensaio universal DL 500 (EMIC). Os valores obtidos foram analisados estatisticamente e apresentaram distribuição normal (ANOVA e TUKEY-HSD). Resultados: Os resultados evidenciaram existir diferença estatisticamente significante entre grupos e en¬tre colagem/recolagem dos bráquetes. A força de colagem inicial demonstrou ser sempre superior à força de recolagem, em todos os grupos experimentais. Conclusões: A força de recolagem dos bráquetes com Rebond® e Transbond® apresentaram forças de adesão adequadas ao uso clínico...

The search for an adhesive material for satisfactory rebond of brackets awakens interest to the orthodontist. The ReBond® fotopolimerizable resin was introduced in Orthodontics with this purpose. Objectives: To assess and compare the performance of in vitro ReBond® with Transbond XT® resin of metallic orthodontic brackets in rebonding. Materials and Method: Ninety bovine lower incisors were divided into 3 groups (n = 30): Group I: brackets bonded with Transbond® resin and bond of new brackets with Transbond® resin; Group II: brackets bonded with Transbond® resin and rebonded with Rebond® resin; Group III: brackets bonded and rebonded with Transbond® resin. Samples were submitted to a shear test in a universal testing machine DL 500 (EMIC). Data were statistically analyzed and showed normal distribution (ANOVA and TUKEY-HSD). Results: The results showed significant difference between groups and between bond/rebond of brackets. The initial bond strength was always higher than the rebond strength in all experimental groups. Conclusions: The strength of rebonding of the brackets rebonded with Rebond® and Transbond® was adequate to the appropriate clinical use...

Endogenous oestradiol but not testosterone is related to coronary artery disease in men.

OBJECTIVES: Men die of coronary artery disease (CAD) more often than women. There is evidence that testosterone either is neutral or has a beneficial effect on male cardiovascular disease. The role of oestrogens in male CAD has been less studied. This study was carried out with the purpose of evaluating the relationship between sex hormone levels and CAD. DESIGN: Case-control study. PARTICIPANTS: Men (aged 40-70) submitted to coronary angiography. A 70% occlusion of at least one major coronary artery defined the cases; subjects with ≤ 50% occlusion constituted the control group. MEASUREMENTS: Blood samples were collected for total testosterone (TT), oestradiol, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, lipid profile and albumin measurements. Bioavailable and free testosterone, free androgen index (FAI) and free oestrogen index (FEI) were calculated. Oestradiol and TT levels were examined as terciles, based on the whole study population. RESULTS: Of the 140 patients included, 72 were cases and 68 were controls. The baseline characteristics of the two groups were similar, except for the older age and lower LDL-C in the cases. Oestradiol and FEI but not total, bioavailable and free testosterone and FAI correlated positively with CAD. After adjustments for potential confounders, oestradiol remained statistically significant. The prevalence of CAD was significantly higher in the 3rd than in the 1st tercile of oestradiol. CONCLUSION: In this study, men with CAD had higher oestradiol and FEI levels. Additional studies are needed to clarify the direction of causality and possible underlying mechanisms.

Prevalence of the polymorphism MTHFR A1298C and not MTHFR C677T is related to chromosomal aneuploidy in Brazilian Turner Syndrome patients / A prevalência do polimorfismo A1298C e não do C677T do gene MTHFR está relacionada à ocorrência de aneuploidias cromossômicas em mulheres brasileiras portadoras da síndrome de Turner

BACKGROUND: Dysfunctions in the folate metabolism can result in DNA hypomethylation and abnormal chromosome segregation. Two common polymorphisms of this enzyme (C677T and A1298C) reduce its activity, but when associated with aneuploidy studies the results are conflicting. The objective of the present study is to analyze the MTHFR gene polymorphisms in women with Turner Syndrome and in a control group, correlating the findings to the chromosomal aneuploidy. METHODS: The study comprised 140 patients with Turner Syndrome, of which 36 with chromosome mosaicism and 104 non-mosaics, and a control group of 209 fertile and healthy women without a history of any offspring with aneuploidy. Polymorphisms C677T and A1298C were studied by RFLP-PCR and the results were statistically analyzed. RESULTS: The frequency of genotypes MTHFR 677CC, 677CT and 677TT in the patients with Turner Syndrome and chromosome mosaicism was, respectively, 58.3 percent, 38.9 percent and 2.8 percent. Among the patients with non-mosaic Turner Syndrome, 47.1 percent presented genotype 677CC, 45.2 percent genotype 677CT, and 7.7 percent genotype 677TT. Among the 209 individuals of the control group, genotypes 677CC, 677CT and 677TT were found at the following frequencies: 48.3 percent, 42.1 percent and 9.6 percent, respectively. As for polymorphism A1298C, the patients with Turner Syndrome and chromosome mosaicism presented genotypes 1298AA, 1298AC and 1298CC at the following frequencies: 58.3 percent, 27.8 percent and 13.9 percent, respectively. Among the non-mosaic Turner Syndrome patients, genotype 1298AA was found in 36.5 percent, genotype 1298AC in 39.4 percent, and genotype 1298CC in 22.1 percent. In the control group, genotypes 1298AA, 1298AC and 1298CC were present at the following frequencies: 52.6 percent, 40.7 percent and 6.7 percent, respectively. CONCLUSION: No correlation was observed between the MTHFR gene polymorphism 677 and chromosomal aneuploidy in the...

INTRODUÇÃO: Disfunções no metabolismo dos folatos podem resultar em hipometilação do DNA e na segregação cromossômica anormal. Dois polimorfismos comuns no gene MTHFR (C677T e A1298C) reduzem a atividade da enzima e, quando associados a estudos de aneuploidias apresentam resultados conflitantes. O objetivo do presente estudo foi a análise dos polimorfismos do gene MTHFR em mulheres portadoras da síndrome de Turner e em indivíduos de grupo-controle, correlacionando os achados ao mecanismo de formação de aneuploidias cromossômicas. MÉTODOS: Foram estudadas 140 portadoras da síndrome de Turner sendo 36 com mosaicismo cromossômico e 104 não-mosaicos, e um grupo-controle composto por 209 mulheres férteis e saudáveis sem história de prole com aneuplodia. Os polimorfismos MTHFR C677T e A1298C foram estudados por RFLP-PCR e os resultados analisados estatisticamente. RESULTADOS: A freqüência dos genótipos MTHFR 677CC, 677CT e 677TT nas pacientes portadoras de síndrome de Turner e mosaicismo cromossômico foi, respectivamente, 58,3 por cento, 38,9 por cento e 2,8 por cento. Das pacientes portadoras de síndrome de Turner não-mosaico, 47,1 por cento apresentaram o genótipo 677CC, 45,2 por cento o genótipo 677CT e 7,7 por cento apresentaram o genótipo 677TT. Nos 209 indivíduos do grupo-controle, os genótipos 677CC, 677CT e 677TT foram encontrados nas seguintes freqüências: 48,3 por cento, 42,1 por cento e 9,6 por cento, respectivamente. Quanto ao polimorfismo A1298C, as portadoras de síndrome de Turner e mosaicismo cromossômico apresentaram os genótipos 1298AA, 1298AC e 1298CC nas seguintes freqüências: 58,3 por cento, 27,8 por cento e 13,9 por cento, respectivamente. Já nas portadoras de Síndrome de Turner não-mosaico, o genótipo 1298AA foi encontrado em 36,5 por cento, o genótipo 1298AC em 39,4 por cento e o genótipo 1298 CC em 22,1 por cento . No grupo-controle, os genótipos 1298AA, 1298AC e 1298CC estavam presentes nas freqüências 52,6 por cento...

Emprego da cromatografia líquida de alta eficiência na determinação de cortisol sérico em substituição à técnica de radioimunoensaio / High-performance liquid chromatography application for serum cortisol quantification as a substitute for radioimmunoassay

Introdução: A determinação de cortisol nos diferentes fluídos orgânicos tem sido aplicada como auxílio diagnóstico em distintas condições nosológicas em humanos, bem como empregada em estudos envolvendo pesquisa clínica. No intervalo de aplicação clínica, rotineiramente é determinado pela técnica de radioimunoensaio (RIE). Na determinação do cortisol urinário livre essa técnica vem sendo substituída peloemprego da cromatografia líquida de alta eficiência (HPLC), principalmente no diagnóstico da síndrome de Cushing. Já para a determinação do cortisol sérico não se têm evidências do emprego da cromatografia líquida em substituição a outras técnicas analíticas. Objetivos: O desenvolvimento de metodologia analítica empregando HPLC no modo fase reversa (RP-HPLC) para a determinação de cortisol sérico em substituição ao RIE visando à redução da geração de resíduos radioativos. Material e métodos: O cortisol foi quantificado diretamente empregando-se RP-HPLC em amostras de soro previamente extraídas com éter utilizando-se acetonido de triancinolona como padrão interno (PI). Utilizou-se coluna analítica BDS-Hypesil-C18® (125 x 4 mm, 5 μm), fase móvel composta de água e acetonitrila (72:28; v/v) a 1 ml/min e detecção a 243 nm. Resultados: O cortisol e o PI apresentaram tempo de retenção de 3,4 e 7,1 min, respectivamente. O coeficiente de variação (CV%) obtido no estudo da precisão foi menor que 10%, e a exatidão apresentou um desvio inferior a 4%. Discussão: O método mostrou-se eficaz e eficiente, com sensibilidade e linearidade na faixa estudada de 2,5 a 60 μg/dl. Conclusão: O método proposto substitui o RIE no intervalo de sua aplicação clínica.

Background: The quantification of cortisol in different organic fluids has not only been applied to different humannosological conditions as a diagnostic aid but it has also been used in clinical research. In clinical application, cortisolis routinely measured by radioimmunoassay (RIA). In the determination of free urinary cortisol this technique has been replaced by the high-performance liquid chromatography mainly in the diagnosis of Cushing syndrome. As to serum cortisol determination, there is no evidence of the application of liquid chromatography as a substitute for other analytical techniques. Objective: The development of an analytical methodology using reversed-phase high-performance liquid chromatography (RP-HPLC) to determine serum cortisol levels as a substitute for RIA in order to reduce radioactive waste. Material and methods: Cortisol was directly quantified by RP-HPLC in previouslyether-extracted serum samples. Triamcinolone acetonide was used as internal standard (IS). The chromatographic separation was developed in a BDS-Hypersil-C18® column (125 x 4 mm, 5μm) using water-acetonitrile (72:28; v/v) as mobile phase at 1 ml/min and steroid peaks were measured at 243 nm. Results: Cortisol and IS presented retention time of 3.4 and 7.1 min, respectively. The precision was less than 10% and accuracy was less than 4%. Discussion: The method was effective and efficient, with good sensitivity and linearity in the concentration range of 2.5 to 60.0μg/dl. Conclusion: The present methodology substitutes RIA at clinical application.

Prevalence of the polymorphism MTHFR A1298C and not MTHFR C677T is related to chromosomal aneuploidy in Brazilian Turner Syndrome patients.

BACKGROUND: Dysfunctions in the folate metabolism can result in DNA hypomethylation and abnormal chromosome segregation. Two common polymorphisms of this enzyme (C677T and A1298C) reduce its activity, but when associated with aneuploidy studies the results are conflicting. The objective of the present study is to analyze the MTHFR gene polymorphisms in women with Turner Syndrome and in a control group, correlating the findings to the chromosomal aneuploidy. METHODS: The study comprised 140 patients with Turner Syndrome, of which 36 with chromosome mosaicism and 104 non-mosaics, and a control group of 209 fertile and healthy women without a history of any offspring with aneuploidy. Polymorphisms C677T and A1298C were studied by RFLP-PCR and the results were statistically analyzed. RESULTS: The frequency of genotypes MTHFR 677CC, 677CT and 677TT in the patients with Turner Syndrome and chromosome mosaicism was, respectively, 58.3%, 38.9% and 2.8%. Among the patients with non-mosaic Turner Syndrome, 47.1% presented genotype 677CC, 45.2% genotype 677CT, and 7.7% genotype 677TT. Among the 209 individuals of the control group, genotypes 677CC, 677CT and 677TT were found at the following frequencies: 48.3%, 42.1% and 9.6%, respectively. As for polymorphism A1298C, the patients with Turner Syndrome and chromosome mosaicism presented genotypes 1298AA, 1298AC and 1298CC at the following frequencies: 58.3%, 27.8% and 13.9%, respectively. Among the non-mosaic Turner Syndrome patients, genotype 1298AA was found in 36.5%, genotype 1298AC in 39.4%, and genotype 1298CC in 22.1%. In the control group, genotypes 1298AA, 1298AC and 1298CC were present at the following frequencies: 52.6%, 40.7% and 6.7%, respectively. CONCLUSION: No correlation was observed between the MTHFR gene polymorphism 677 and chromosomal aneuploidy in the Turner Syndrome patients. However, the MTHFR gene polymorphism at position 1298, mainly genotype 1298CC that reduces the enzyme efficiency, was more frequent in the group of Turner Syndrome patients, suggesting its involvement in mechanisms related to chromosomal imbalances.