Genotipificación del gen RHD en ADN fetal libre en plasma de embarazadas RhD negativo / Genotyping of the RHD gene in free fetal DNA in plasma of RhD negative pregnant women

Objetivo: Determinar el grupo RhD fetal a través del estudio del gen RHD en ADN fetal que se encuentra libre en plasma de embarazadas RhD negativo. Método: Se analizó la presencia de los genes RHD, SRY y BGLO en ADNfl obtenido de plasma de 51 embarazadas RhD negativo no sensibilizadas, utilizando una qPCR. Los resultados del estudio genético del gen RHD se compararon con el estudio del grupo sanguíneo RhD realizado por método serológico en muestras de sangre de cordón, y los resultados del estudio del gen SRY fueron cotejados con el sexo fetal determinado por ecografía. Se calcularon la sensibilidad, la especificidad, los valores predictivos y la capacidad discriminativa del método estandarizado. Resultados: El gen RHD estaba presente en el 72,5% de las muestras y el gen SRY en el 55,5%, coincidiendo en un 100% con los resultados del grupo RhD detectado en sangre de cordón y con el sexo fetal confirmado por ecografía, respectivamente. Conclusiones: Fue posible deducir el grupo sanguíneo RhD del feto mediante el estudio del ADN fetal que se encuentra libre en el plasma de embarazadas con un método molecular no invasivo desarrollado y validado para este fin. Este test no invasivo puede ser utilizado para tomar la decisión de administrar inmunoglobulina anti-D solo a embarazadas RhD negativo que portan un feto RhD positivo.

Objective: To determine the fetal RhD group through the study of the RHD gene in fetal DNA found free in plasma of RhD negative pregnant women. Method: The presence of the RHD, SRY and BGLO genes in fetal DNA obtained from plasma of 51 non-sensitized RhD negative pregnant women was analyzed using qPCR. The results of the genetic study of the RHD gene were compared with the RhD blood group study performed by serological method in cord blood samples, and the results of the SRY gene study were compared with the fetal sex determined by ultrasound. Sensitivity, specificity, predictive values and discriminative capacity of the standardized method were calculated. Results: The RHD gene was present in 72.5% of the samples and the SRY gene in 55.5%, coinciding 100% with the results of the RhD group detected in cord blood, and with the fetal sex confirmed by ultrasound, respectively. Conclusions: It was possible to deduce the RhD blood group of the fetus through the study of fetal DNA found free in the plasma of pregnant women with a non-invasive molecular method developed and validated for this purpose. This non-invasive test can be used to make the decision to administer anti-D immunoglobulin only to RhD-negative pregnant women carrying an RhD-positive fetus.

Características ecográficas y anomalías congénitas en fetos con síndrome de Down / Ultrasound features and congenital anomalies in fetuses with Down syndrome

Resumen Objetivo: Describir y analizar los hallazgos ecográficos en 97 fetos portadores de síndrome de Down (SD) confirmado. Método: Se incluyeron todas las gestantes con diagnóstico prenatal de SD de nuestro centro, realizado por cariograma o reacción en cadena de la polimerasa cuantitativa fluorescente para aneuploidía. Se analizaron los informes genéticos y ecográficos, y se realizó un seguimiento posnatal. Resultados: De los 97 casos de SD, el 73% de los diagnósticos fueron entre las 11 y 14 semanas. El promedio de edad de las madres fue de 35,7 años. El 83% de los fetos con SD, evaluados a las 11-14 semanas, tuvieron una translucencia nucal ≥ 3,5 mm. Del total de los casos analizados, el 33% fueron portadores de una cardiopatía congénita, correspondiendo el 58% de estas a defectos mayores, principalmente anomalías del tabique auriculoventricular. Un 7,6% de los casos terminaron como mortinato, principalmente durante el tercer trimestre. Conclusiones: El ultrasonido es una herramienta muy sensible para la sospecha prenatal de SD y la detección de sus anomalías asociadas. Consideramos que la información aportada será útil para programar estrategias de pesquisa, organizar el control perinatal y precisar el consejo a los padres de fetos portadores de esta condición.

Abstract Objective: To describe and analyze the ultrasound findings in 97 fetuses with confirmed Down syndrome (DS). Method: All pregnant women with prenatal diagnosis of DS in our center, performed by karyotype or quantitative fluorescent polymerase chain reaction for aneuploidy, were included. Genetic and ultrasound reports were analyzed, as well as postnatal follow-up. Results: Of the 97 cases of DS, 73% of the diagnoses were between 11-14 weeks. The average age of the mothers was 35.7 years. 83% of our fetuses with DS, evaluated between 11-14 weeks, had a nuchal translucency ≥ 3.5 mm. Of the total of the fetuses analyzed, 33% were carriers of congenital heart disease, 58% of these correspond to a major defect, mainly anomalies of the atrioventricular septum. 7.6% of cases ended as stillbirth, mainly during the third trimester. Conclusions: Ultrasound is a very sensitive tool for prenatal suspicion of DS and the detection of its associated abnormalities. We believe that the information provided will be useful to program screening strategies, organize perinatal control and to counselling parents of fetuses carrying this condition.

Quiste renal simple / Simple Renal Cyst

Los quistes renales simples son poco frecuentes en recién nacidos, niños y adolescentes. Suelen ser únicos, y ocasionalmente múltiples. No existen evidencias de riesgo familiar. El objetivo de la presentación fue resaltar la importancia del diagnóstico precoz de malformaciones congénitas y/o defectos estructurales del feto, por ultrasonografía, en la atención primaria de salud. Presentamos las imágenes ecográficas de un caso de afectación fetal por un quiste renal simple a las 36 semanas, sin otros hallazgos ultrasonográficos. Previo asesoramiento genético y dado la avanzada edad gestacional y el buen pronòstico con que cursan estos casos además de no tener otro defecto genético asociado, la pareja decidió la continuación del embarazo. El caso fue confirmado por ecografía posnatal(AU)

Simple renal cysts are rare in newborns, children and adolescents. They tend to be unique, and occasionally multiple. There is no evidence of family risk. The objective of the presentation was to highlight the importance of early diagnosis of congenital malformations and / or structural defects of the fetus, by ultrasonography, in primary health care. We present the echography of a case of fetal involvement by a simple renal cyst at 36 weeks, with no other ultrasonography findings. The parents decided to continue the pregnancy previous genetic counseling, given the advanced gestational age and good prognosis with these cases, and considering there is no other genetic defect associated. The case was confirmed by postnatal ultrasound(AU)

Diagnóstico prenatal y manejo perinatal en enfermedades raras / Prenatal diagnosis and management of rare diseases

El diagnóstico y manejo prenatal de enfermedades raras involucra un estudio multidisciplinario. Desde una visión obstétrica, herramientas de imagenología como la ultrasonografía y en menor medida la resonancia magnética fetal (RMF) son esenciales para el diagnóstico de anomalías morfológicas y sospecha de defectos cromosómicos. Para el diagnóstico de enfermedades cromosómicas el estudio de cariograma obtenido de vellosidades coriales, líquido amniótico o sangre fetal mediante técnicas invasivas tal como biopsia corial, amniocentesis o cordocentesis ha sido hasta hace poco el gold standard del diagnóstico. Nuevas técnicas moleculares capaces de detectar microdeleciones como es el microarray nos ha permitido aproximarnos al origen de las enfermedades raras. Se revisarán además algunos de los defectos anatómicos raros y su enfoque neonatal.

Prenatal diagnosis and management of rare diseases is a multidisciplinary task. From the obstetric vision, prenatal diagnosis is based on fetal images obtained by ultrasound or magnetic resonance and fetal chromosomes study. The study of fetal morphology allows us the diagnosis of fetal abnormalities and the suspicion of chromosomal defects. Fetal chromosomal study is obtained either by chorionic villus sampling, amniocentesis and cordocentesis, all associated to fetal risk. New screening techniques such as fetal DNA on maternal blood or the study of fetal micro deletions using micro Array on amniotic fluid has extended diagnostic opportunity of rare fetal diseases. We will review some of the most common rare diseases and the neonatal approach.

Análise dos resultados maternos e fetais dos procedimentos invasivos genéticos fetais: um estudo exploratório em Hospital Universitário / Analysis of fetal and maternal results from fetal genetic invasive procedures: an exploratory study at a University Hospital

OBJETIVO: Caracterizar as indicações das gestantes que procuraram o serviço de Medicina Fetal do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo para realização de procedimentos invasivos diagnósticos e avaliar os resultados dos cariótipos fetais e de suas gestações. MÉTODOS: Estudo observacional retrospectivo das gestantes que realizaram biópsia de vilo corial (BVC), amniocentese e cordocentese no período de fevereiro de 2005 a dezembro de 2009. Não foram incluídos outros procedimentos diagnósticos ou procedimentos terapêuticos. O resultado da gestação foi obtido através de consulta de prontuário eletrônico e/ou físico e/ou contato telefônico. RESULTADOS: Foram realizados 713 procedimentos (113 BVC, 340 amniocenteses e 260 cordocenteses). A principal indicação para a realização dos procedimentos invasivos foi a presença de alterações estruturais nos fetos, seguido por valores aumentados da translucência nucal e pela idade materna avançada. O cariótipo fetal esteve alterado em 186 casos (26,1%). A trissomia do cromossomo 18 foi a aneuploidia mais comum, seguida pela trissomia do 21, a monossomia do X e a trissomia do cromossomo 13. Ocorreram 4,9% de abortamento, 25,7% de natimortos e 13% de neomortos. Oito gestantes optaram pela interrupção judicial, e 99% das gestantes cujos fetos não apresentavam malformação e que apresentavam cariótipo fetal normal tiveram nativivos.

OBJECTIVE: To characterize the indications of pregnant women who sought the Fetal Medicine Services of the Hospital das Clínicas, at the Medical School of the Universidade de São Paulo for performing invasive diagnostic procedures, and to evaluate the results of fetal karyotypes and their pregnancies. METHODS: A retrospective and observational study on pregnant women who underwent chorionic villus sampling (CVS), amniocentesis, and cordocentesis in the period from February, 2005 to December, 2009. Other diagnostic or therapeutic procedures were not included. The result of pregnancy was obtained by consulting patient electronic records, medical records, and/or telephone call. RESULTS: 713 procedures were performed (113 CVS, 340 amniocenteses, and 260 cordocenteses). The main indication for performing invasive procedures was the presence of structural changes in fetuses, followed by increased values of nuchal translucency, and advanced maternal age. Fetal karyotype was altered in 186 cases (26.1%). The 18 trisomy was the commonest aneuploidy followed by the 21 trisomy, X monosomy, and 13 trisomy. There were 4.9% cases of miscarriage, 25.7% cases of stillborn infants, and 13% cases of neonatal deaths. Eight pregnant women opted for legally induced abortion. 99% of pregnant women whose fetuses did not present abnormalities and presented normal fetal karyotype had infants who were born alive.

Diagnóstico pré-natal utilizando material fetal isolado do sangue periférico materno / Prenatal diagnosis using fetal material isolated from maternal peripheral blood

As anomalias cromossômicas apresentam grande incidência entre os nativivos e natimortos, constituindo a maior causa de morte fetal em países desenvolvidos, no período perinatal. Tradicionalmente, o diagnóstico dessas cromossomopatias é feito por procedimentos invasivos, que não são isentos de complicações materno-fetais. O desenvolvimento de técnicas que permitem identificação e o isolamento de células fetais e de DNA fetal livre no sangue periférico materno tem permitido o diagnóstico precoce das anomalias cromossômicas, tornando-se, desse modo, uma área de intensas pesquisas. Estudos mais recentes também envolvem a identificação e quantificação de mRNA fetal na circulação materna, o que torna possível a análise da expressão gênica fetal durante a gestação. O resgate de material fetal em sangue periférico materno e sua utilização no diagnóstico de várias doenças fetais é uma área de grande interesse na medicina fetal atual. Estudos são necessários para se avaliar melhor o papel propedêutico dessas novas técnicas, assim como sua aplicabilidade na prática clínica rotineira.

Chromosomal abnormalities show great incidence among live birth and stillbirth, becoming the major fetal death cause during the perinatal period in developed countries. Traditionally, the diagnosis of these chromosomal abnormalities is performed through invasive techniques which are not free from maternal-fetal complications. The development of techniques that allows identification and isolation of fetal cells and free fetal DNA in peripheral maternal blood has afforded the early diagnosis of chromosomal abnormalities and, therefore, become an intensive area of research. Recent studies describe the identification and qualification of fetal mRNA in the maternal circulation, which makes possible fetal gene expression analysis during pregnancy. The identification of fetal material in maternal circulation and its value on the diagnosis of several fetal diseases is a great area of interest in the current fetal medicine. Studies are necessary to evaluate the best propedeutic role of these new techniques, as well as their applicability in the routine clinical practice.

Reconstrução nasal neonatal na Síndrome do Warfarin Fetal / Neonatal nasal reconstruction in Fetal Warfarin Syndrome

O objetivo deste trabalho é relatar um caso de reconstrução nasal precoce em um paciente com síndrome do Warfarin fetal, onde um paciente de 23 dias com apresentava hipoplasia nasal isolada. O ganho ponderal estava estagnado e não havia possibilidade de introdução de sonda nasoentérica devido à deformidade. Foi realizada rinoplastia aberta com incisão transcolumelar. Dois enxertos de cartilagem tragal foram confeccionados e introduzidos na região da ponta, porção cranial do septo cartilaginoso e alares. O paciente apresentou melhoria da permeabilidade ventilatória, diminuição do ruído inspiratório, ganho de peso e também da forma. Após um ano de seguimento o resultado continuava satisfatório. Concluímos que a intervenção precoce é satisfatória e pode minimizar ou mesmo prevenir procedimentos futuros.

The aim of this work is to report a case of early nasal reconstruction in a 23-day-old patient with fetal Warfarin syndrome and isolated nasal hypoplasia. Weight gain was arrested and the deformity precluded the use of a nasogastric tube. An open rhinoplasty with transcolumellar incision was performed. Two grafts of tragal cartilage were made and introduced in the tip area, cranial portion of the cartilaginous septum, and alar cartilages. The patient presented improved ventilatory permeability, decrease of inspiratory noise, and weight and shape gains. At the one-year follow-up the result was still satisfactory. We concluded that early intervention is satisfactory and may minimize or even prevent future procedures.

Consideraciones éticas del uso de la ultrasonografía 11-14 semanas como tamizaje de aneuploidías en la población Chilena / Nuchal translucency thickness screening for aneuploidies in the Chilean population: ethical considerations

El examen ultrasonográfico entre las 11-14 semanas de gestación para pesquisa de aneuploidías en el feto se está realizando sistemáticamente en muchos centros asistenciales de nuestro país. Si bien la utilidad diagnóstica de este examen está ampliamente validada, surgen dudas sobre sus reales beneficios y los potenciales riesgos de este método, utilizado como tamizaje, en nuestra población. Esta presentación tiene como objetivo hacer una reflexión sobre esos riesgos y beneficios. Se discuten la utilización de este procedimiento sin un adecuado consentimiento informado, y las implicancias que tiene la instauración rutinaria de este método en el control obstétrico de nuestra población, especialmente al considerar las condiciones en las que en muchos centros se realiza este examen.

The ultrasound screening for aneuploidies between the 11 and 14 weeks of gestation is systematically performed in many centers of our country. Although the usefulness of this diagnostic test is well known, concern has been raised regarding its potential risks, when used as a screening method. The aim of this article is to analyze the risk and benefits of this practice in our population, considering the frequent lack of an informed consent and how is this procedure performed in several medical centers in our country.

Nuevas perspectivas en el síndrome de QT largo / New perspectives in long QT syndrome

Long QT Syndrome (LQTS) is a cardiac channelopathy characterized by prolonged ventricular repolarization and increased risk to sudden death secondary to ventricular dysrrhythmias. Was the first cardiac channelopathy described and is probably the best understood. After a decade of the sentinel identification of ion channel mutation in LQTS, genotype-phenotype correlations have been developed along with important improvement in risk stratification and genetic guided-treatment. Genetic screening has shown that LQTS is more frequent than expected and interestingly, ethnic specific polymorphism conferring increased susceptibility to drug induced QT prolongation and torsades de pointes have been identified. A better understanding of ventricular arrhythmias as an adverse effect of ion channel binding drugs, allow the development of more safety formulas and better control of this public health problem. Progress in understanding the molecular basis of LQTS has been remarkable; eight different genes have been identified, however still 25% of patients remain genotype-negative. This article is an overview of the main LQTS knowledge developed during the last years.

El síndrome de QT largo (SQTL) es una canalopatía que genera grave alteración en la repolarización ventricular predispone a arritmias malignas y muerte súbita. Fue la primera canalopatía arritmogénica descrita y quizá la mejor entendida hasta ahora. Transcurrida ya más de una década de la identificación de la primera mutación asociada al SQTL, se ha hecho evidente que este trastorno es mucho más frecuente de lo que inicialmente se pensaba; los avances en el conocimiento de la fisiopatología molecular de esta enfermedad han permitido hacer una correlación genotipo-fenotipo, optimizando el tratamiento y permitiendo estratificar el riesgo en forma precisa. Se ha logrado entender con mayor detalle los efectos adversos de distintas drogas que interactúan con los canales iónicos, permitiendo así generar fármacos más seguros y, en su defecto, monitorizar de cerca aquellos que a pesar de tener este efecto adverso, es necesaria su administración. Los avances son importantes pero no todo está dicho, 25% de los casos no tienen mutaciones en los genes descritos hasta la fecha, por lo que el SQTL continúa siendo motivo de investigación. El presente artículo constituye un resumen de los principales conceptos desarrollados en los últimos diez años que han sido cruciales en el manejo de esta enfermedad.

Síndrome de Pallister-Killian: diagnóstico antenatal por ultrasonografía 2D y 3D / Pallister-Killian syndrome: antenatal diagnosis by 2D and 3D ultrasonography

El síndrome de Pallister-Killian o tetrasomía 12p en mosaico, asocia una dismorfia facial característica y la presencia de un cromosoma supernumerario, interpretado como un isocroma del brazo corto del cromosoma 12. Es una entidad raramente descrita en la literatura con una incidencia menor a 1 x 10.000; aumentando con la edad materna. Se sospecha en período antenatal principalmente ante la presencia de una hernia diafragmática aislada o asociada a una dismorfia facial, fémur corto, nuca gruesa o cardiopatía sin restricción de crecimiento. Se presenta el caso de un paciente de 44 años, los hallazgos por medio de la ultrasonografía bi y tridimensional, así como la revisión de la literatura.

Atrioventricular septal defect--associated anomalies and aneuploidy in prenatal life.

The present study was conducted to estimate the frequency of other-cardiac, extracardiac and chromosomal anomalies in fetuses with A VSD diagnosed in a prenatal diagnosis center, analysed from the database during the 54-month period extending from November 1997 to May 2002. One hundred and three fetuses were diagnosed with A VSD. Among them other-cardiac and extra cardiac anomalies were present in 56 and 75 cases respectively. Of the 22 fetuses that had undergone karyotyping, no metaphase was seen in one case. In the remaining 21, 15 (71.4%) turned out to be normal, three (14.2%) had trisomy 18, two (9.5%) had trisomy 13 and one had trisomy 21 (4.8%). We found that AVSD almost always occurs with other-cardiac or extracardiac anomalies, though the pattern may differ between populations. It seems to be less frequently associated with chromosomal anomalies (especially trisomy 21) in South India. The genetics of AVSD underscores the importance of a thorough understanding of the target population in prenatal decision-making.

Partial Trisomy 2q(2q37.3->qter)and Monosomy 7q(7q34->qter) Due to Paternal Reciprocal Translocation 2;7: A Case Report

We report an unbalanced translocation involving chromosome 2 and 7 due to a balanced reciprocal translocation 2;7 in the father. The female fetus had a partial trisomy of the long arm of chromosome 2 with a partial monosomy of distal 7q. Ultrasound at the first trimester had indicated normal fetal anatomy, including normal intracranial structures. Parental karyotypes showed a paternal balanced translocation: 46,XY,t(2;7)(q37.3;->q34). The unbalanced translocation in the fetus resulted in trisomy for 2q37.3 qter and monosomy for 7q34->qter. Postnatal examination showed that the female abortus had a cleft lip and palate, and mild dysmorphic features. The clinical phenotype was in agreement with previous descriptions and allowed us to propose a fetal phenotype for this chromosomal abnormality.

Alto risco genético: aspectos neonatais / Genetic high risk: neonatal aspects

O trabalho ressalta a importância do reconhecimento adequado dos defeitos congênitos no recém-nascido, analisando as manifestaçöes clínicas das doenças genéticas no período neonatal, e estudando as malformaçöes congênitas isoladas e associadas, deformidades e disrupçöes. Através de numerosas figuras, quadros e tabelas, o autor ilustra os vários aspectos do tema abordado

Alto risco genético: aspectos obstétricos / Genetic high risk: obstetrical aspects

O artigo trata da atençäo ao alto risco genético, por parte do especialista, no período pré-nupcial, no pré-natal e após abortamentos ou nascimento de feto malformado. Destaca o valor da amniocentese, ultra-sonografia e da amostra da vilo corial e analisa a conduta do médico diante do R.N. malformado