Expert consensus on the detection of genome-wide copy number variations in abortive tissues and family reproductive consultation / 中华医学遗传学杂志

Chromosomal aberrations including numerical abnormalities and segment duplications/deletions, as genome-wide copy number variations (CNVs), are a leading cause for spontaneous abortion. Analysis of abortive tissues for such CNVs can detect potential genomic variations in the couple and provide guidance for the choice of appropriate method to avoid further miscarriage or birth of child with chromosomal disorders. With evidence-based clinical data, an expert group jointly formed by the Genetic Disease Prevention and Control Group, Committee for Birth Defects Prevention and Control, Chinese Association of Preventive Medicine; the Clinical Genetics Group, the Society of Medical Genetics, Chinese Medical Association; the Professional Committee for Prenatal Diagnosis of Genetic Diseases, the Society of Medical Geneticists, Chinese Medical Doctor Association has discussed and formulated this consensus, with an aim to provide guidance for the application of genomic CNVs detection for the abortive tissue and genetic counseling for family reproduction.

Analysis of genetic etiology and related factors in 1 065 women with spontaneous abortions / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology and related factors in 1 065 women with spontaneous abortions.@*METHODS@#All patients have presented at the Center of Prenatal Diagnosis of Nanjing Drum Tower Hospital from January 2018 to December 2021. Chorionic villi and fetal skin samples were collected, and the genomic DNA was assayed by chromosomal microarray analysis (CMA). For 10 couples with recurrent spontaneous abortions but normal CMA results for abortive tissues, non-in vitro fertilization-embryo transfer (IVF-ET) pregnancies and no previous history of live births and no structural abnormalities of the uterus, peripheral venous blood samples were collected. Genomic DNA was subjected to trio-whole exome sequencing (trio-WES). Candidate variants were verified by Sanger sequencing and bioinformatics analysis. Multifactorial unconditional logistic regression analysis was carried out to analyze the factors that may affect chromosomal abnormality in spontaneous abortions, such as the age of the couple, number of previous spontaneous abortions, IVF-ET pregnancy and history of live birth. The incidence of chromosomal aneuploidies in spontaneous abortions during the first trimester was compared in young or advanced-aged patients by chi-square test for liner trend.@*RESULTS@#Among the 1 065 spontaneous abortion patients, 570 cases (53.5%) of chromosomal abnormalities were detected in spontaneous abortion tissues, which included 489 cases (45.9%) of chromosomal aneuploidies and 36 cases (3.4%) of pathogenic/likely pathogenic copy number variations (CNVs). Trio-WES results have revealed one homozygote variant and one compound heterozygote variants in two pedigrees, both of which were inherited from the parents. One likely pathogenic variant was detected in the patient from two pedigrees. Multifactorial unconditional Logistic regression analysis suggested that age of patient was an independent risk factor of chromosome abnormalities (OR = 1.122, 95%CI: 1.069-1.177, P < 0.001), the number of previous abortions and IVF-ET pregnancy were independent protective factors for chromosomal abnormalities (OR = 0.791, 0.648; 95%CI: 0.682-0.916, 0.500-0.840; P = 0.002, 0.001), whilst the age of husband and history of live birth were not (P > 0.05). The incidence of aneuploidies in the abortive tissues has decreased with the number of previous spontaneous abortions in young patients (χ² = 18.051, P < 0.001), but was not significantly correlated with the number of previous spontaneous abortions in advanced-aged patients with spontaneous abortions (P > 0.05).@*CONCLUSION@#Chromosomal aneuploidy is the main genetic factor for spontaneous abortion, though CNVs and genetic variants may also underlie its genetic etiology. The age of patients, number of previous abortions and IVF-ET pregnancy are closely associated with chromosome abnormalities in abortive tissues.

Alteraciones citogenéticas en pacientes con diagnóstico de infertilidad en Lima, Perú / Cytogenetic abnormalities in patients with infertility diagnosis in Lima, Peru

INTRODUCCIÓN: La infertilidad es una enfermedad multicausal y el componente genético representa uno de sus principales eventos. Si bien la distribución de la infertilidad puede variar entre poblaciones, las parejas de los países con bajos y medianos ingresos pueden verse más afectadas por la infertilidad, con una proporción de alteraciones citogenéticas aún no esclarecidas. OBJETIVO: Evaluar la frecuencia de alteraciones citogenéticas y su correlación con el número de abortos en pacientes peruanas con diagnóstico de infertilidad. MÉTODO: Se realizó un estudio de corte transversal en 400 pacientes de 18 a 60 años, de ambos sexos, con diagnóstico de infertilidad. Se registraron las características clínicas disponibles durante el examen genético y el análisis citogenético convencional fue con bandeo GTG en muestras de sangre periférica. El análisis de correlación se realizó con la prueba de Spearman. RESULTADOS: Del total, 389 pacientes cumplieron los criterios de inclusión, y de estos, 169 (43,44%) tuvieron reportes de abortos (promedio: 2,25, rango: 1-7). Hallamos una correlación significativa ente el número de abortos y las alteraciones citogenéticas (p < 0,000). Reportamos 25/289 (6,43%) alteraciones cromosómicas, de las que 11/25 (44%) fueron heterocromatinas constitutivas y 6/25 (24%) fueron translocaciones reciprocas. Las alteraciones citogenéticas más frecuentes fueron 16qh+ y 9qh+ (ambas con un 16%), y afectaron a 17 (68%) varones. CONCLUSIONES: Existe una moderada frecuencia de alteraciones citogenéticas en pacientes peruanos con diagnóstico de infertilidad, y las alteraciones más frecuentes fueron heterocromatina constitutivas. Además, evidenciamos una correlación significativa ente el número de abortos y las alteraciones citogenéticas.

INTRODUCTION: Infertility is a multicausal disease and the genetic component represents one of its main events. Although the distribution of infertility may vary between populations, couples in low-and-middle-income countries may be more affected by infertility with a proportion of cytogenetic alterations still unclear. OBJECTIVE: To evaluate the frequency of cytogenetic alterations and their correlation with the number of abortions in Peruvian patients with a diagnosis of infertility. METHOD: A cross-sectional study was carried out in 400 patients between 18 and 60 years-old, of both genders with a diagnosis of infertility. The clinical characteristics available during the genetic examination were recorded and the conventional cytogenetic analysis was with GTG banding in peripheral blood samples. The correlation analysis was performed with the Spearman test. RESULTS: Of the total 389 patients who met the inclusion criteria, of these 169 (43.44%) patients had reports of abortions (mean: 2.25, range: 1-7). We found a significant correlation between the number of abortions and cytogenetic alterations (p < 0.000). We report 25/289 (6.43%) chromosomal alterations, where 11/25 (44%) were constitutive heterochromatin, and 6/25 (24%) were reciprocal translocations. The most frequent cytogenetic alterations were 16qh + and 9qh + (both 16%), and affected 17 (68%) men. CONCLUSIONS: There is a moderate frequency of cytogenetic alterations in Peruvian patients diagnosed with infertility, where the most frequent alterations were constitutive heterochromatin. Furthermore, we evidenced a significant correlation between the number of abortions and cytogenetic alterations.

Application of copy number variation sequencing combined with short tandem repeat in analysis of abortion and prenatal diagnosis / 中华医学遗传学杂志

OBJECTIVE@#To explore the cause of abortion and strategy of prenatal diagnosis for pregnant women with high risk for chromosomal abnormalities by using copy number variation sequencing (CNV-seq) and short tandem repeats (STR) analysis.@*METHODS@#A total of 36 samples were collected, including amniotic fluid, abortion tissue, whole blood, chorionic villi and umbilical cord blood. CNV-seq and STR analysis were carried out to detect microdeletions, microduplications, chromosomal aneuploidies, mosaicisms and triploidies.@*RESULTS@#Among all samples, 1 was detected with 4p15.1p16.3 and 14q11.1q22.1 duplication, 1 was detected with 19p13.3 deletion, 8 were detected with chromosomal aneuploidies, 4 were detected with mosaicisms, two were detected with triploidies. No definite pathogenic CNVs were detected in 20 samples, which yielded a positive detection rate of 44.44%.@*CONCLUSION@#As a high-throughput detection method, CNV-seq has the advantages of rapidity, simplicity and high accuracy. It may suit prenatal diagnosis and analysis of abortion factors in combination with STR analysis.

Factors associated with spontaneous abortion: a systematic review / Fatores associados ao aborto espontâneo: uma revisão sistemática

Abstract Objectives: to compile studies produced regardinggenetic and non-genetic risks factors associated with occurrence of spontaneous abortion. Methods: it talks about a systematic review article, with studies between January of 2008 to November of 2018 according to SciELO, PubMed, Lilacs and BVS. Results: in total, 567 articles were found. After applying the definedeligibility criteria, 44 articles made part of the review, being the majority published on Asia between 2008 and 2011, and 10 articles published on Brazil. Not genetic causes like sociodemographic factors and healthy state were among the most associated conditions of spontaneous abortion. Asiatic continent had predominance about the correlation of spontaneous abortion with factors related to life style like obesity, smoking and labor activities, on the other hand, in the Americas, causes related to sociodemographics factors like low pay and low studies are high-lighted. Conclusions: the risk factors change about the occurrence region, being important to make local studies capable of subsidize the implantation of public politics and to reduce abortions.

Resumo Objetivos: compilar estudos produzidos acerca dos fatores de risco genéticos e não genéticos associados a ocorrência de aborto espontâneo. Métodos: trata-se de um artigo de revisão sistemática, com estudos publicados entre janeiro de 2008 a novembro de 2018 nas bases de dados SciELO, PubMed, Lilacs e BVS. Resultados: um total de 567 artigos foram encontrados. Após aplicação dos critérios de elegibilidade definidos, 44 artigos compuseram a presente revisão com a maioria publicada na Ásia, entre os anos de 2008 a 2011, e 10 artigos publicados no Brasil. Causas não genéticas, como fatores sociodemográficos e estado de saúde, estiveram entre as condições mais associadas ao abortamento espontâneo. No continente asiático houve predominância na correlação do aborto espontâneo com fatores relacionados ao estilo de vida como obesidade, tabagismo e atividades laborais; já nas Américas destacam-se causas relacionadas aos fatores sociodemográficos, como baixa renda e baixa escolaridade. Conclusões: os fatores de risco diferem em relação a região de ocorrência, sendo importante a realização de estudos detalhados para que sejam capazes de subsidiar a implantação de políticas públicas e, assim, minorar a ocorrência de abortos.

Frequency of Chromosomal Abnormalities in Products of Conception / Frequência de anomalias cromossômicas em material de aborto

Abstract Purpose To describe the frequencies of chromosomal abnormalities found in abortion material, and to observe its correlation to maternal age. Methods A retrospective study was conducted based on data obtained from the databank of a medical genetics laboratory in Belo Horizonte, MG, Brazil. A total of 884 results from products of conception analysis were included, 204 of which were analyzed by cytogenetics, and 680bymolecular biology basedon quantitative fluorescence polymerase chain reaction (QF-PCR). The frequency of individual chromosomal aberrations and the relationship between the presence of anomalies and maternal age were also evaluated. Results The conventional cytogenetics technique was able to detect 52% of normal and 48% of abnormal results in the analyzed material. Quantitative fluorescence polymerase chain reaction revealed 60% of normal and 40% of abnormal results from the samples evaluated by this method. The presence of trisomy 15 was detected only by cytogenetics, as it was not included in the QF-PCR routine investigation in the laboratory. A significant increase in abnormal results was observed among women aged 35 years or older compared with younger women (p = 0.02). Conclusion Chromosomal aberrations are still a major cause of spontaneous abortion, and the conventional cytogenetics technique is efficient for miscarriage material analysis, but molecular methods such as QF-PCR are adequate complementary strategies to detect the major chromosomal anomalies, leading to technical reports with reliable results.

Resumo Objetivos Descrever a frequência de anomalias cromossômicas encontradas em material de aborto, e observar se estas estão relacionadas com a idade materna. Métodos Foi realizado um estudo retrospectivo no banco de dados de um laboratório de genética médica em Belo Horizonte, MG. O estudo incluiu 204 resultados avaliados por citogenética, e 680 resultados por biologia molecular baseada em reação em ensaio fluorescente da reação em cadeia da polimerase (QF-PCR), totalizando um número de 884 análises. A frequência de diferentes anomalias cromossômicas e a relação entre a presença de anomalias e a idade materna também foi avaliada. Resultados A citogenética convencional foi capaz de detectar 52% de resultados normais e 48% de resultados anormais no material analisado. A QF-PCR revelou 60% de resultados normais e 40% de anormais nas amostras avaliadas por esta técnica. A presença da trissomia 15 foi detectada por citogenética,mas até então não era incluída na investigação por QF-PCR no laboratório. Umaumento significativo na quantidade de resultados anormais foi observado em mulheres comidade de 35 anos ou mais, quando comparado a mulheres mais jovens (p = 0,02). Conclusão As aberrações cromossômicas são causas importantes de abortos espontâneos, e o estudo citogenético é eficaz para a análise das amostras de material de aborto, mas as técnicas moleculares, como a QF-PCR, representam métodos complementares adequados para detectar as principais anomalias cromossômicas, possibilitando a liberação de laudos com resultados confiáveis.

Estudio cromosómico en abortos espontáneos / Chromosome study in spontaneous abortions

Aproximadamente 15 por ciento de todos los embarazos clínicos terminan en aborto espontáneo. La causa más frecuente de aborto espontáneo es una anomalía cromosómica fetal, tal como una trisomía autosómica, monosomía X y poliploidía. Desde mayo de 1991 hasta febrero de 2013 hemos realizado 2.416 estudios citogenéticos en restos de aborto en la Sección Citogenética del Laboratorio Clínico de Clínica Alemana de Santiago, Chile. Deseamos compartir la información sobre la distribución de los hallazgos en estos estudios, así como difundir la estrategia que hemos implementado desde febrero de 2010 con estudio de varias sondas de hibridación in situ con fluorescencia (FISH) en aquellos casos en que el cultivo no ha progresado, lo que permite entregar alguna información importante respecto a la presencia o ausencia de ciertas alteraciones cromosómicas en todos los estudios.

Approximately 15 percent of all clinical pregnancies end in spontaneous abortion. The most common cause of spontaneous abortion is a fetal chromosomal abnormality, such as an autosomal trisomy, monosomy X and polyploidy. From May 1991 until February 2013 we performed 2,416 cytogenetic studies in abortion tissues in the Cytogenetics Unit of the Clinical Laboratory Clínica Alemana de Santiago. We want to share information about the distribution of the findings in these studies, and want to disseminate the strategy we have implemented since February 2010 with multiple probes study of fluorescence in situ hybridization (FISH) in cases where the tissue culture had not progressed, allowing to provide some important information regarding the presence or absence of certain chromosomal abnormalities in all studies.

study of chromosomal abnormalities and heteromorphism in couples with 2 or 3 recurrent abortions in Shahid Beheshti hospital of Hamedan

Different studies show that chromosomal balance translocation in the parents can cause recurrent spontaneous abortions. Incidence of chromosomal translocation abnormalities in couples with repeated abortions is from 0% to 31%. The purpose of this research was studying the presence or absence of chromosomal abnormalities and heteromorphism in couples with recurrent abortions and also the role of this anomaly in the abortions. This study is a cross sectional descriptive study which have investigated 75 couples who had three abortions or more, and 65 couples who had two abortions that referred by gynecologist to the lab of Beheshti Hospital in Hamedan for cytogenetical investigation. Also 40 healthy individuals without history of abortion investigated as control group.GTG bonding technique [staining banding with gymsa and trypsin] is used in this study. Frequency of chromosomal abnormalities and heteromorphism among couples with three or more abortions were reported respectively 5.3% and 9.3%. This frequency in couples with two abortions was respectively 3.07%and 6.15%. The frequency of chromosomal heteromorphism in control group was 7.5% and no chromosomal abnormalities were observed in them. This study shows that chromosomal abnormality can be one reason of recurrent spontaneous abortions and more abortion increases the probability of this anomaly. Also, existence of chromosomal heteromorphism in the general population without clinical abortion symptoms shows that chromosomal heteromorphism cannot be the reason of these spontaneous abortions

Estudio citogenético en 677 casos de aborto espontáneo / Cytogenetic study of 677 spontaneous abortions

INTRODUCCIÓN: La reproducción humana es un proceso relativamente ineficaz. Los abortos espontáneos ocurren entre el 15 a 20 por ciento de los embarazos clínicamente reconocidos. El impacto emocional se acentúa debido a la falta de diagnóstico. OBJETIVO: Describir la experiencia del Laboratorio de Citogenética de la Clínica Sanatorio Alemán de Concepción e identificarlas alteraciones más frecuentes y su relación estadística con la edad materna. MATERIAL Y MÉTODO: 677 muestras de tejido obtenidas de abortos espontáneos, ocurridos desde julio de1996 a abril de 2009. Es un trabajo de tipo transversal donde las muestras utilizadas son las vellosidades coriónicas, cultivadas en medios estandarizados. RESULTADOS: De las 677 muestras estudiadas, en 259 se obtuvo un cariotipo normal (38,3 por ciento). En 418 muestras se encontraron anomalías cromosómicas, correspondiendo estas a un 61,7 por ciento. Entre los cariogramas alterados se encontraron: 265 trisomías (63,4 por ciento), 83 poliploidías (19,9 por ciento), 48 monosomías (11,5 por ciento) y 22 alteraciones estructurales (5,3 por ciento). La trisomía más frecuente fue la 16 (34,4 por ciento), seguida de la trisomía 21 (13,6 por ciento). Se encontró una relación estadísticamente significativa entre la edad de la madre (> 37 años) y la presencia de alteraciones citogenéticas (p<0,0001). DISCUSIÓN: El 61,7 por ciento de los abortos presentó alguna alteración del cariotipo. La trisomía 16 fue la aberración más frecuente concordando con la literatura. La trisomía 21 se presentó en un 13,6 por ciento siendo más frecuente que lo encontrado en series extranjeras. En el grupo mayor de 37 años existe mayor prevalencia de anomalías cromosómicas siendo estadísticamente significativa (p<0,0001).

INTRODUCCION: The human reproduction is a relatively inefficient process. In the 15 to 20 percent of the pregnancy clinically diagnosticated finish in spontaneous abortions. The great emotional impact, that in many times is worst by the lack of diagnostic. OBJECTIVE: Describe experience of the Cytogenetic Laboratory of Clínica Sanatorio Alemán of Concepción Chile and determinate the frequency of alteration and his relationship with maternal age. MATERIAL AND METHOD: 677 samples of tissue of spontaneous abortions, taked from July, 1996 to April, 2009. It is a descriptive work; the samples are chorionic villous, cultivated in standard solutions. RESULTS: Of 677 samples in 259 was found a normal cariotype (38.3 percent). In 418 was found some type of chromosome aberrations (61.7 percent). The distribution of the abnormal result is the follow: 265 trisomies (63.4 percent), 83 polyploidy (19.8 percent), 48 monosomy (11.5 percent) and 22 abnormalities structures (5.3 percent). Of the trisomies the most recurrent is 16 trisomy with the 34.4 percent, follow by the 21 trisomy with 13.6 percent and the 22 trisomy with 12.8 percent. In the statistic analysis we found a statistically significant relation between the age of the mother (<38 years) and the development of chromosomal alterations (p<0.0001). DISCUSSION: The 61.7 percent of abortions show some cytogenetic alteration. The 16 trisomies were the most frequent, agreeing with the literature. The trisomy 21 was more common than published to date. In older women is most frequent found chromosome aberrations (p<0.0001).

The ADA*2 allele of the adenosine deaminase gene (20q13.11) and recurrent spontaneous abortions: an age-dependent association

OBJECTIVE: Adenosine deaminase acts on adenosine and deoxyadenosine metabolism and modulates the immune response. The adenosine deaminase G22A polymorphism (20q.11.33) influences the level of adenosine deaminase enzyme expression, which seems to play a key role in maintaining pregnancy. The adenosine deaminase 2 phenotype has been associated with a protective effect against recurrent spontaneous abortions in European Caucasian women. The aim of this study was to investigate whether the G22A polymorphism of the adenosine deaminase gene is associated with recurrent spontaneous abortions in Brazilian women. METHODS: A total of 311 women were recruited to form two groups: G1, with a history of recurrent spontaneous abortions (N = 129), and G2, without a history of abortions (N = 182). Genomic DNA was extracted from peripheral blood with a commercial kit and PCR-RFLP analysis was used to identify the G22A genetic polymorphism. Fisher's exact test and odds ratio values were used to compare the proportions of adenosine deaminase genotypes and alleles between women with and without a history of recurrent spontaneous abortion (p<0.05). The differences between mean values for categorical data were calculated using unpaired t tests. The Hardy-Weinberg equilibrium was assessed with a chi-square test. RESULTS: Statistically significant differences were identified for the frequencies of adenosine deaminase genotypes and alleles between the G1 and G2 groups when adjusted for maternal age. CONCLUSIONS:The results suggest that the adenosine deaminase *2 allele is associated with a low risk for recurrent spontaneous abortions, but this association is dependent on older age.

Análise citogenética em material de abortamento espontâneo / Cytogenetic analysis of material from spontaneous abortion

OBJETIVO: Descrever as anormalidades cromossômicas em material de abortamento espontâneo. MÉTODOS: Realizou-se compilação retrospectiva da análise de cariótipo em lâmina corada com Banda G por microscopia óptica e em material de 428 produtos de abortamento encaminhados para estudo. RESULTADOS: Foram observados 145 resultados normais (33,9 por cento) e 237 resultados anormais (55,4 por cento). Em 46 amostras não houve crescimento celular (10,7 por cento). As anormalidades numéricas foram as mais frequentes, destacando-se a trissomia do 16 (41 casos), a triplodia (27 casos), a monossomia do X (26 casos), a tetraploidia (13 casos) e a trissomia do 15 (13 casos). CONCLUSÃO: As alterações citogenéticas representam importante causa de perdas gestacionais e sua detecção auxilia o aconselhamento genético do casal. A trissomia do cromossomo 16 é a alteração mais frequentemente encontrada.

OBJECTIVE: To describe chromosomal abnormalities in spontaneous abortion material. METHODS: A retrospective compilation of karyotype analysis of slides stained with Band G was carried out by optical microscopy with materials of 428 abortion products referred for study. RESULTS: There were 145 normal results (33.9 percent) and 237 abnormal results (55.4 percent). In 46 samples there was no cell growth (10.7 percent). Numerical abnormalities were the most frequent, especially trisomy 16 (41 cases), triplodia (27 cases), monosomy X (26 cases), tetraploidy (13 cases) and trisomy 15 (13 cases). CONCLUSION: Cytogenetic alterations are an important cause of pregnancy loss and their detection helps the genetic counseling to the couple. Trisomy 16 is the most often found change.

Maternal MTHFR polymorphisms and risk of spontaneous abortion / Polimorfismos maternos MTHFR y riesgo de aborto espontáneo

OBJECTIVE: To asses the association between intake of folate and B vitamins and the incidence of spontaneous abortion (SA) according to the maternal methylenetetrahydrofolate reductase (MTHFR) polymorphisms (677 C>T and 1298 A>C). MATERIAL AND METHODS: We conducted a nested case-control study within a perinatal cohort of women recruited in the state of Morelos, Mexico. Twenty-three women with SA were compared to 74 women whose pregnancy survived beyond week 20th. Intake of folate and B vitamins respectively, was estimated using a validated food frequency questionnaire. Maternal MTHFR polymorphisms were determined by PCR-RFLP and serum homocysteine levels by HPLC. RESULTS: Carriers of MTHFR 677TT and 1298AC genotypes respectively showed an increased risk of SA (OR 677TT vs. CC/CT=5.0; 95 percent CI: 1.2, 20.9 and OR 1298 AC vs. AA=5.5; 95 percent CI: 1.1, 26.6). CONCLUSIONS: Our results support the role of MTHFR polymorphisms as a risk factor for SA, regardless of dietary intake of B vitamins.

OBJETIVO: Evaluar la asociación entre aborto espontáneo (AE) y el consumo dietético de vitaminas B en mujeres mexicanas portadoras de los polimorfismos de la metilentetrahidrofolato reductasa (MTHFR) (677 C>T y 1298 A>C). MATERIAL Y MÉTODOS: Mediante un diseño de casos y controles anidados en una cohorte, se comparó la ingesta dietética materna de vitaminas B y folato, los polimorfismos maternos de la MTHFR y la concentración sérica de homocisteina de 23 casos de AE (< 20 semanas) y 74 controles (mujeres con embarazos > 20 semanas). RESULTADOS: Las portadoras de los genotipos MTHFR 677TT y 1298AC presentaron un incremento significativo en el riesgo de AE (RM 677TT vs. CC/CT=5.0; IC 95 por ciento: 1.2, 20.9 RM 1298 AC vs. AA=5.5; IC95 por ciento: 1.1, 26.6), respectivamente. CONCLUSIONES: Nuestros resultados apoyan el papel de la mutación de la MTHFR como posible factor de riesgo para el AE, independientemente del consumo de vitaminas B.

Anomalias e prognóstico fetal associados à translucência nucal aumentada e cariótipo anormal / Fetal abnormalities and prognosis associated with increased nuchal translucency and abnormal karyotype

OBJETIVO: Descrever a frequência de anomalias cromossômicas em fetos com translucência nucal (TN) aumentada, e a frequência de malformações estruturais, a evolução e o resultado da gestação nos fetos com TN aumentada e cariótipo anormal. MÉTODOS: Estudo retrospectivo envolvendo 246 casos com medida da TN acima do percentil 95º para a idade gestacional, com cariótipo fetal conhecido ou avaliação clínica das crianças no período pós-natal. Os casos foram acompanhados no setor de Medicina Fetal do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo. RESULTADOS: O resultado do cariótipo fetal esteve alterado em 14,2 por cento dos casos. O acompanhamento dessas gestações revelou anormalidade estruturais em 80,8 por cento dos fetos, sendo as anormalidades cardíacas as mais comuns (61,5 por cento). Resultados gestacionais adversos, como abortamento, óbitos intraútero e neonatal ocorreram em 76,5 por cento dos fetos. CONCLUSÃO: Translucência nucal aumentada, entre 11 - 13 semanas e 6 dias, é importante marcador de anomalias cromossômicas fetais e malformações estruturais fetais, principalmente cardíacas. Diante deste achado, há aumento do risco de abortamento, óbito intrauterino e neonatal para estas gestações.

OBJECTIVES: This study aimed to evaluate the incidence of chromosomal abnormalities in fetuses with increased nuchal translucency (NT) measurement. Incidence of structural abnormalities and pregnancy outcome was also described in fetuses with increased NT and abnormal karyotype. METHODS: This was a retrospective study involving 246 fetuses with increased NT and known karyotype followed at the Fetal Medicine Unit, Hospital das Clínicas, São Paulo University Medical School. RESULTS: Fetal karyotype was abnormal in 14.2 percent of the cases. Ultrasound anomaly scan and specialized echocardiographic studies in these cases showed fetal structural abnormalities in 80.8 percent and cardiac defects were found in 61.5 percent of the fetuses. Pregnancy outcome was abnormal in 76.5 percent of these women. CONCLUSION: Increased NT measurement at 11 to 13 weeks and 6 days is an important marker for fetal chromosomal and structural abnormalities, mainly fetal cardiac defects. This finding also indicates increased risk of spontaneous fetal and neonatal death.

Polimorfismos gênicos da metilenotetrahidrofolato redutase, cistationina beta-sintetase e metionina sintase: associação a perdas fetais recorrentes e níveis séricos de vitamian B12, folatos e hemocisteína / Polymorphisms of metilenotetrahidrofolato reductase gene, cystathionine beta-synthase and methionine synthase: association with recurrent fetal losses and serum vitamian B12, folate and hemocisteína

A patogênese dos abortos espontâneos envolve interação complexa de diversos fatores genéticos e ambientais. A homocisteína é um aminoácido envolvido em diversos processos metabólicos incluindo metilação e sulfuração, sendo que as concentrações plasmáticas de homocisteína são determinadas por fatores nutricionais, como a ingestão de folatos e vitamina BI2, e de variações na atividade de enzimas decorrentes da presença de polimorfismos gênicos. Atualmente, a elevação da homocisteína plasmática e a deficiência de folatos e vitamina BI2 têm sido associadas a problemas obstétricos, incluindo o aborto espontâneo recorrente. O objetivo deste trabalho foi investigar associações entre os polimorfismos presentes em genes responsáveis pela síntese de proteínas envolvidas no metabolismo da homocisteína e seus substratos e ocorrência de aborto espontâneo recorrente. Foram investigados os polimorfismos C677T e A1298C no gene da enzima metilenotetrahidrofolato redutase (MTHFR); o polimorfismo A2756G no gene da enzima metionina sintase (MS) e a inserção 844ins68 no gene da enzima cistationina beta sintetase (CBS), utilizando o técnica de PCR - RFLP. Os níveis séricos de homocisteína, vitamina BI2 e folatos foram determinados pela técnica de quimioluminescência. As freqüências a1élicas dos po1imorfismos entre 89 mulheres com história de abortos recorrentes e 150 controles foram de 19,1 por cento e 19,6 por cento, respectivamente, para o polimorfismo C677T da MTHFR; 20,8 por cento e 26,0 por cento, respectivamente,para o polimorfismo A1298C da MTHFR; 14,2 por cento e 21,9 por cento, respectivamente, para o polimorfismo A2756G da MS; e 16,4 por cento e 18,0 por cento, respectivamente, para a inserção 844ins68 da CBS. No presente estudo não foram encontradas diferenças significativas entre as freqüências dos polimorfismos nos grupos de mulheres investigadas.

Abordagem citogenética e molecular em material de abortos espontâneos / Cytogenetic and molecular evaluation of spontaneous abortion samples

OBJETIVOS: avaliar o desempenho da citogenética e das técnicas de hibridização in situ fluorescente (FISH) e reação em cadeia da polimerase (PCR) no estudo das aneuploidias cromossômicas numéricas e na determinação do sexo fetal em amostras de abortos espontâneos. MÉTODOS: duzentos e dezenove amostras de produtos de abortos espontâneos foram submetidas a estudo citogenético. Deste total, 40 amostras foram também submetidas à técnica de PCR-nested para a determinação do sexo fetal: 32 foram selecionadas devido à falha de crescimento no estudo citogenético e oito foram escolhidas ao acaso. Vinte amostras foram selecionadas para detecção de aneuploidias cromossômicas pela técnica de FISH, utilizando-se sondas para os cromossomos 13, 18, 21, X e Y: 13 casos foram submetidos a FISH devido à falha de crescimento no estudo citogenético e sete foram escolhidos ao acaso. Foi calculada a taxa de sucesso (obtenção de cariótipo) de cada técnica. Para comparação das taxas de sucesso foi utilizado o teste de chi2, sendo considerados significantes resultados com p<0,05. Foi avaliado o índice de acerto entre os resultados das amostras submetidas a mais de um exame, tomando-se como padrão-ouro o resultado do estudo citogenético. RESULTADOS: houve crescimento celular em 84,9 por cento das amostras submetidas a análise citogenética. Em 51,1 por cento dos casos foram encontradas alterações cromossômicas: 65,2 por cento trissomias, 17,9 por cento triploidias, 9,4 por cento tetraploidias, 4,2 por cento monossomia do cromossomo X e 1,1 por cento trissomia dupla, tetrassomia e alteração estrutural. A trissomia mais freqüente foi a do cromossomo 16 (39 por cento). FISH e PCR tiveram taxa de sucesso de 90 por cento, não diferindo significativamente do exame citogenético. Em todos os casos submetidos a mais de um exame os resultados foram concordantes. Nas amostras com falha de crescimento celular no exame citogenético e submetidas a outra técnica, a PCR obteve sucesso em 87,5 por cento e a FISH em 84,6 por cento. CONCLUSAO: o estudo citogenético de restos ovulares de abortamentos espontâneos teve elevada taxa de sucesso e evidenciou anomalias cromossômicas em mais da metade dos casos. As técnicas de biologia molecular (PCR-nested e FISH) complementaram o estudo citogenético e permitiram a obtenção de resultados seguros na detecção de alterações cromossômicas numéricas e na determinação do sexo fetal

Consanguinity on Kahramanmaras city, Turkey, and its medical impact

Recently, several studies have indicated the rate of consanguinity ranging between 20 and 70% in the Middle East. Turkey is one of the countries with a high rate of consanguineous unions in the Middle East. In this study, the rate of consanguinity and its effects on spontaneous abortus, stillbirth, infant mortality, and birth defects were investigated in a population sample residing in Kahramanmaras city, Turkey. For this study, 1000 randomly selected women, aboriginals of Kahramanmaras city, Turkey, were interviewed at their home and the concerning information was obtained by administration of a questionnaire between April 2002 and March 2003. The prevalence of consanguinity was found to be 30.6% with the mean inbreeding coefficient of 0.015373. The most common type of consanguineous mating was first cousin marriages with the frequency of 22.6%. The family pressure and love were the main reasons for marrying with a relative. The mean age at marriage of women and men were lower in consanguineous marriages than that of non-consanguineous unions. There was a negative correlation between the consanguinity and educational level of both sexes. The results revealed differences between consanguineous and non-consanguineous matings, in terms of stillbirth, infant mortality and birth defects whereas the rate of spontaneous abortus was found to be the same in 2 kinds of marriages. The incidence of consanguinity and of first cousin marriages is found to be very high in the Kahramanmaras city. A reduction of consanguinity rate is necessary for the health quality of the population

X-chromosome Inactivation Patterns in Korean Women with Idiopathic Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) defines as two or more consecutive losses at or =90%) and 4 (8.9%) had mild skewed inactivation (> or =85%). In 54 heterozygous control subjects, 5 (9.3%) women showed extreme skewed X inactivation and 7 (13.0%) had mild one. The frequency of skewed X inactivation between RSA patients and control group was not significantly different (p>0.05). This finding suggests that skewed x romosome be not associated with unexplained RSA patients.

Investigação genética dos abortamentos espontâneos pelo DNA / Genetic investigation of spontaneous abortions by DNA techniques

Os abortamentos espontâneos são fenômenos comuns, mas emocionalmente devastadores. Uma explicação científica da causa da perda fatal é fundamental para o casal poder restaurar a sua homeostase emocional e para o médico orientar a sua conduta. Mais de 50% dos abortamentos apresentam anormalidades cromossômicas, especialmente trissomias (60%), triploidia (15%) e monossomia X (15%). Assim, o cariótipo fetal deve ser feito, se possível, em todos os casos de perda gestacional. Os estudos cromossômicos convencionais dependem da cultura de células fetais estar associada com falhas de crescimento in vitro e contaminação com células maternas. Uma alternativa vantajosa é a citogenética molecular, que estuda o cariótipo fatal diretamente ao nível do DNA, dispensando a cultura de tecidos e permitindo até a análise de espécimes fixados em formol, etanol ou incluídos em parafina. Este artigo descreve a implantação no GENE - Núcleo de Genética Médica - de uma metodologia própria de estudos genéticos de abortamentos usando a reação em cadeia da polimerase (PCR) e permitindo o diagnóstico das principais trissomias, da triploidia e da monossomia X. Neste trabalho fazemos uma revisão da análise de 1.096 abortamentos estudados por três protocolos diferentes: citogenética convencional (Protocolo 1), citogenética convencional + citogenética molecular (Protocolo 2), ou citogenética molecular isoladamente (Protocolo 3). O nosso objetivo foi comparar resultados obtidos após a implantação dos estudos moleculares com os resultados anteriores. A conclusão do estudo foi que o procedimento de citogenética molecular implantado é simples, eficiente e de baixo custo e representa uma ferramenta de grande utilidade clínica.

Spontaneous abortions are common, but emotionally devastating events. A scientific explanation of the cause of the fetal death is important for the parents to restore their emotional homeostasis and for the physicians involved plan their conduct. More than 50% of miscarriages have chromosomal abnormalities, especially trisomies (60%), triploidy (15%) and monosomy X (15%). Thus, a fetal karyotype should be obtained in all abortions, if possible. Conventional chromosome studies depend on fetal cell cultures and are thus associated with growth failures in vitro and contamination with maternal cells. An advantageous alternative to conventional methods is molecular cytogenetics, which is based on studying the fetal karyotype directly at the DNA level. This has the advantage of dispensing with tissue culture and allows analysis even of specimens fixed in ethanol or formaldehyde or included in paraffin. We wish to describe the development at GENE — Núcleo de Genética Médica — of a methodology for the molecular cytogenetic study of miscarriages using the polymerase chain reaction (PCR), permitting the diagnosis of the most common trisomies, of triploidy and of monosomy X. In this article we review the results of 1,096 abortion specimens studies by one of three protocols: conventional cytogenetics (Protocol 1), conventional cytogenetics + molecular cytogenetics (Protocol 2) and molecular cytogenetics alone (Protocol 3). Our objective was to compare data obtained with molecular cytogenetics with previous results. The conclusion was that the protocols developed with the use of molecular techniques are simple, efficient and inexpensive and represent a tool of great clinical usefulness.