Epidemiología del diagnóstico prenatal de defectos congénitos en la provincia de Holguín / Epidemiology of prenatal diagnosis of congenital defects in Holguín province

Introducción: En Cuba, los defectos congénitos constituyen la segunda causa de muerte en niños menores de un año, por lo cual ocupan un lugar prioritario en los programas médicos sociales del país. Objetivo: Evaluar el comportamiento epidemiológico del diagnóstico prenatal de los defectos congénitos en Holguín, Cuba. Métodos: Se realizó un estudio descriptivo y transversal de la epidemiología de los defectos congénitos en la provincia de Holguín, Cuba, en el periodo de enero 2011- junio de 2020. Resultados: Los años con mayor número de defectos congénitos diagnosticados fueron: 2011, 2012, 2017 y 2018 con 308, 253, 290 y 236 pacientes, respectivamente. Los defectos congénitos más frecuentes fueron: cardiovasculares (comunicación interventricular, canal auriculoventricular, transposición de grandes vasos e hipoplasia de cavidades), renales (pielocaliectasia, hidronefrosis, riñones poliquísticos), y del sistema nervioso central (ventriculomegalia, hidrocefalia). El grupo de edad materna donde se realizó mayor número de diagnósticos fue entre 20-24 años, la mayoría en el segundo trimestre de la gestación; en el primer trimestre, el mayor número de defectos congénitos correspondió a los defectos de pared anterior. La tasa de mortalidad infantil por defectos congénitos se mantuvo estable en la mayoría de los años estudiados. Conclusiones: La estabilidad y perfeccionamiento del programa de diagnóstico prenatal de los defectos congénitos, y el asesoramiento genético adecuado, han tenido un resultado epidemiológico favorable en la provincia.

Introduction: congenital defects in Cuba are the second cause of death in children under one year of age that is why they occupy a priority place in the social medical programs of the country. Objective: to evaluate the epidemiological manifestation of the prenatal diagnosis of congenital defects in Holguín, Cuba. Methods: a descriptive and cross-sectional study of the epidemiology of birth defects was carried out in Holguín province, Cuba from January 2011 to June 2020. Results: the years with the highest number of diagnosed birth defects were 2011, 2012, 2017 and 2018 with 308, 253, 290 and 236 patients, respectively. The most frequent birth defects were cardiovascular (ventricular septal defect, atrioventricular canal, transposition of the great vessels and hypoplasia of cavities), renal (pyelokaliectasia, hydronephrosis and polycystic kidneys), and central nervous system (ventriculomegaly and hydrocephalus). The maternal age group in which the highest number of diagnoses was made was between 20-24 years, mostly in the second trimester of pregnancy; the largest number of congenital defects in the first trimester corresponded to anterior wall defects. The infant mortality rate due to congenital defects remained stable in most of the years studied. Conclusions: the stability and improvement of the prenatal diagnosis program for congenital defects, as well as an adequate genetic counseling, have had a favourable epidemiological result in the province.

Diagnóstico prenatal, síndrome Freeman-Sheldon mediante ultrasonido y estudio genético. Reporte de caso / Prenatal diagnosis of Freeman-Sheldon syndrome using ultrasound and genetic testing. Case report

Objetivos: Describir un caso de diagnóstico prenatal de síndrome de Freeman-Sheldon mediante hallazgos ecográficos y secuenciación completa del exoma fetal. Materiales y métodos: Mujer de 33 años, con antecedentes de hipotiroidismo en tratamiento, a quien en semana 19 se realizó ecografía de detalle anatómico, en la cual se observaron deformidades en el feto en más de dos áreas corporales (extremidades superiores e inferiores), sugiriendo el diagnóstico de artrogriposis. Posteriormente, se brindó asesoría genética y se realizó amniocentesis en semana 20 de gestación, con análisis de la hibridación in situ por fluorescencia, seguido de secuenciación completa del exoma fetal. Este último examen permitió identificar una variante patogénica heterocigota en el gen MYH3, la cual se asocia con la artrogriposis distal tipo 2A. Conclusiones: La realización de la secuenciación completa de exoma fetal es un factor clave para identificar la mutación del gen MYH3, y confirma que las deformidades evidenciadas por ultrasonido estaban relacionadas con la artrogriposis distal tipo 2A. Es importante hacer la secuenciación de exoma fetal en fetos que muestren hallazgos de malformaciones articulares en el ultrasonido prenatal.

Objectives: To describe a case of prenatal diagnosis of Freeman-Sheldon syndrome based on ultrasound findings and complete fetal exome sequencing. Materials and methods: A 33-year-old woman currently on treatment for hypothyroidism in whom a 19-week detailed anatomical ultrasound scan showed fetal deformities in more than two body areas (upper and lower limbs), suggesting a diagnosis of arthrogryposis. Genetic counseling was provided and amniocentesis was performed at 20 weeks for fluorescence in situ hybridization (FISH) analysis and complete fetal exome sequencing, with the latter allowing the identification of a heterozygous pathogenic variant of the MYH3 gene which is associated with type 2A distal arthrogryposis. Conclusions: Complete fetal exome sequencing was a key factor in identifying the MYH3 gene mutation and confirmed that the deformities seen on ultrasound were associated with type 2A distal arthrogryposis. It is important to perform complete fetal exome sequencing in cases of joint malformations seen on prenatal ultrasound.

Factores de riesgo asociados a anomalías congénitas renales y de vías urinarias / Risk factors associated with congenital renal and urinary tract anomalies

Introducción: Las anomalías congénitas renales y de las vías urinarias constituyen la principal causa de enfermedad renal crónica en la edad pediátrica. Su etiología es multifactorial. Intervienen factores maternos, genéticos y ambientales. En Cuba, las afecciones congénitas del riñón y las vías urinarias constituyen una latente preocupación y aunque se ha incrementado el diagnóstico prenatal de las mismas, el número de pacientes diagnosticados es alto. Objetivo: Contribuir al conocimiento de la comunidad científica en relación con los factores de riesgo asociados a las anomalías del desarrollo renal. Métodos: Se realizó una revisión sistemática de la literatura médica disponible en las bases de datos Ebsco, SciELO, Scopus, Pubmed, revistas de nefrología pediátrica, pediatría, genética y teratología; y en la red social académica: Researchgate. Se accedió, durante los últimos cinco años, a varios artículos publicados en español y en inglés. Se utilizaron los descriptores Congenital anomalies of the kidney and urinary tract, hydronephrosis, risk factors, prenatal diagnosis, congenital abnormalities. Conclusiones: La presencia de la diabetes, desde la etapa preconcepcional y durante las primeras semanas del embarazo, la obesidad, las dietas maternas bajas en proteínas, y las alteraciones de la fertilidad, se asocian a las anomalías del desarrollo renal. Existen factores de riesgo específicos para determinados tipos de defectos congénitos renales y de las vías urinarias. No se considera, que el consumo del ácido fólico tenga un papel protector sobre las alteraciones de la embriogénesis renal, por lo que se recomienda ser cauteloso con la dosis que se administra a las embarazadas.

Introduction: congenital renal and urinary tract anomalies are the main cause of chronic kidney disease in children. Its etiology is multifactorial. Maternal, genetic and environmental factors are involved. In Cuba, congenital renal and urinary tract affections constitute a latent concern, and although their prenatal diagnoses have increased, the number of diagnosed patients is high. Objective: to contribute to the knowledge of the scientific community in relation to the risk factors associated with renal developmental anomalies. Methods: a systematic review of the available medical literature was carried out in Ebsco, SciELO, Scopus and Pubmed databases, in pediatric nephrology, pediatrics, genetics, and teratology journals as well as in the academic social network: Researchgate. Several articles published in Spanish and English languages were accessed during the last five years. The used descriptors were congenital anomalies of the kidney and urinary tract, hydronephrosis, risk factors, prenatal diagnosis and congenital abnormalities. Conclusions: the presence of diabetes, from the preconceptional stage and during the first weeks of pregnancy, obesity, maternal diets low in protein, and fertility disorders, are associated with renal developmental anomalies. There are specific risk factors for certain types of kidney and urinary tract birth defects. It is not considered that the consumption of folic acid has a protective role on the alterations of renal embryogenesis, so it is recommended to be cautious with the dose administered to pregnant women.

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.

Câncer de colo uterino na gestação / Cervical cancer in pregnancy

PONTOS-CHAVE • A incidência de câncer durante a gestação tem aumentado devido à tendência das mulheres em postergar a gravidez. O câncer de colo de útero é a terceira neoplasia mais comumente diagnosticada durante o período gestacional. • O rastreamento e o diagnóstico devem se dar como nas pacientes não gestantes; a citologia oncótica cervical é o exame obrigatório do pré-natal, e a colposcopia com biópsia pode ser realizada em qualquer período da gestação. • A gestação complicada pelo diagnóstico de um câncer deve sempre ser conduzida em centro de referência e por equipe multidisciplinar. • A interrupção da gestação em situações específicas, para tratamento-padrão, é respaldada por lei. • A quimioterapia neoadjuvante é uma alternativa segura de tratamento durante a gestação, para permitir alcançar a maturidade fetal. Apresenta altas taxas de resposta, sendo relatada progressão neoplásica durante a gestação em apenas 2,9% dos casos. O risco de malformações fetais decorrentes da quimioterapia é semelhante ao da população geral. Contudo, a quimioterapia está associada a restrição de crescimento intraútero, baixo peso ao nascer e mielotoxicidade neonatal. • Na ausência de progressão de doença, deve-se levar a gestação até o termo.

Resultados materno y perinatal de pacientes con diagnóstico prenatal de gastrosquisis en un centro de Medellín / Maternal and perinatal outcomes of patients with prenatal diagnosis of gastroschisis in a center in Medellin

Objetivo: Describir los resultados maternos y perinatales de pacientes con diagnóstico prenatal de gastrosquisis atendidos en un centro de referencia obstétrica de Medellín. Método: Estudio observacional, descriptivo y retrospectivo, llevado a cabo en la Clínica Universitaria Bolivariana en fetos con diagnóstico prenatal de gastrosquisis desde el 1 de enero de 2010 hasta el 31 de julio de 2021. Resultados: Se identificaron 54 gestantes con diagnóstico prenatal de gastrosquisis. En el 63% era su primer embarazo y el 27,8% eran adolescentes. La duración promedio de la gestación fue de 35 semanas y 6 días. La cesárea fue la vía más común (98,1%) y la indicación más frecuente fue sufrimiento de asa 66,7%. El 55,6% de los neonatos requirieron más de una intervención quirúrgica para el cierre de la pared abdominal. Las complicaciones más frecuentes fueron anemia (66,7%) e íleo posoperatorio (72,2%). La mortalidad fue del 13%. Conclusiones: Se evidencian algunas características similares a las reportadas en otras series. La mayor presentación fue en primer embarazo, la causa de finalización de la gestación fue sufrimiento de asas (demostrando la importancia del seguimiento ecográfico), y las complicaciones más frecuentes fueron anemia e íleo posoperatorio presentados por la prematuridad. La mortalidad comparada con la de otras instituciones locales fue menor.

Objective: To describe the outcomes of maternal and perinatal in patients diagnosed with prenatal gastroschisis that received medical care at an obstetric reference center in Medellin. Method: Observational, descriptive and retrospective study in fetuses with a prenatal diagnosis of gastroschisis performed in the Clínica Universitaria Bolivariana between January 1st 2010 and July 31st 2021. Results: Were included 54 pregnant women with prenatal diagnosis of gastroschisis. The 63% were their first pregnancy and 27,8% were adolescents. The average duration of gestation was 35 weeks and 6 days. Cesarean section was the most common way of delivery (98,1%) and the most frequent indication was suffering from loop (66,7%). The 55,6% of neonates required more than one surgical intervention for closure of the abdominal wall. The most frequent complications were anemia (66,7%) and postoperative ileus (72,2%). A mortality of 13% was presented. Conclusions: Some characteristics like reported in other series are evident. The greatest presentation was in the first pregnancy, the cause of termination of pregnancy was suffering from loops (demonstrating the importance of ultrasound monitoring) and the most frequent complications were anemia and postoperative ileus presented by prematurity. Mortality, compared to other local institutions, was lower.

Diagnóstico antenatal de cardiopatías congénitas por telemedicina: experiencia en CERPO, 2017-2022 / Antenatal diagnosis of congenital heart disease by telemedicine: experience in CERPO, 2017-2022

Introducción: Las cardiopatías congénitas son las anomalías más frecuentes y la principal causa de muerte infantil y neonatal. El diagnóstico prenatal mejora el resultado perinatal determinando el lugar de nacimiento y el nivel de cuidado neonata. La telemedicina mediante videoconferencia en tiempo real permite mejorar la precisión diagnóstica y planificar el nacimiento. Objetivo: Determinar el diagnóstico y manejo perinatal de fetos con sospecha de cardiopatía congénitas, evaluadas a través de telemedicina en tiempo real atendidas en CERPO en el periodo 2017-2022. Material y métodos: Estudio retrospectivo de las evaluaciones mediante telemedicina en tiempo real realizadas en CERPO entre los años 2017 a 2022. Se revisó el resultado perinatal y se compararon los diagnósticos pre y postnatales, extraídos de la base de datos CERPO y Unidad de Neonatología del Hospital Luis Tisné Brousse. Resultados: La correlación del diagnóstico de cardiopatía congénita mediante telemedicina es de un 81,8% y de 89,8% con el diagnostico posnatal. Conclusiones: La evaluación por medio de telemedicina permite mejorar la precisión diagnostica de la cardiopatía congénita en áreas con escaso acceso a operadores experimentados en evaluación cardiaca fetal. Esto minimiza el impacto económico y social asociado al manejo perinatal de un feto con cardiopatía congénita en nuestro país.

Introduction: Congenital heart disease is the most common anomaly and the leading cause of infant and neonatal death. Prenatal diagnosis improves perinatal outcomes by choosing the right place of birth and level of neonatal care. Telemedicine by videoconferencing in real-time allows for improved diagnostic accuracy and birth planning. Objective: To determine the diagnosis and perinatal management of fetuses with suspected congenital heart disease, evaluated by telemedicine at CERPO in the period 2017-2022. Material and Methods: Retrospective study of evaluations via real-time videoconferencing performed at CERPO between 2017-2022. The perinatal outcome was reviewed, and pre and postnatal diagnoses were compared. The data was extracted from the CERPO database and the Neonatology Unit of the Luis Tisné Brousse Hospital. Results: The correlation of congenital heart disease diagnosis by telemedicine was 81.8% and 89.8% with postnatal diagnosis. Conclusions: Telemedicine assessment improves the diagnostic accuracy of congenital heart disease in areas with poor access to an experienced fetal cardiac specialist. This minimizes the economic and social impact associated with our countrys perinatal management of a fetus with congenital heart disease.

Hipospadias: del diagnóstico ecográfico prenatal al manejo posnatal / Hypospadias: from prenatal ultrasound diagnosis to postnatal management

El hipospadias es la localización anormal del meato urinario y es la malformación de genitales externos más frecuentemente diagnosticada. El diagnóstico prenatal es posible mediante ecografía sistemática desde la semana 20 de gestación, siendo más fácil su diagnóstico en el tercer trimestre. Las formas leves suelen ser aisladas, familiares o asociadas a disfunción placentaria o restricción de crecimiento intrauterino, mientras que las formas más graves presentan hasta un 30% de asociación a defectos fetales, anomalías cromosómicas/genéticas o anomalías del desarrollo sexual. La tríada para el diagnóstico ecográfico prenatal consiste en curvatura ventral del pene, anomalía del prepucio dorsal y punta del pene roma. La valoración de la uretra durante la micción y el aspecto del chorro miccional son de gran utilidad para clasificar el defecto. Cuando se diagnostica hipospadias peneano o escrotal es aconsejable realizar una amniocentesis para estudio genético fetal y valorar otros signos de adecuada virilización, como el descenso testicular a partir de la semana 27. El seguimiento tras el parto debe ser multidisciplinario, incluyendo urólogo y endocrinólogo infantil. En hipospadias leves el pronóstico es bueno con reparación quirúrgica en el primer año de vida, pero las formas graves pueden presentar un reto mayor para su corrección funcional y estética.

Hypospadias refers to the abnormal location of the meatus; it is the most common genital malformation detected in the fetus and newborn. Prenatal diagnosis is feasible from 20 weeks onwards with routine ultrasound; however, it is easier to diagnose during the third trimester of pregnancy. Mild defects are usually isolated, familiar o related to placental disfunction or intrauterine growth restriction, while the severe hypospadias are associated to other fetal defects, genetic or chromosomal abnormalities or disorders of sex development. In about 30% of cases. The triad of ultrasound findings prenatally is ventral curvature of the penis, redundant dorsal foreskin and blunt distal penis. The identification of the urethra during the micturition and the direction of the urinary stream help in the classification of the defect. When severe hypospadias is detected, the recommendation is to perform genetic amniocentesis and search for other ultrasound findings related to poor virilization in the fetus, as testicular descent after 27 weeks of gestation. Postnatal follow up should be multidisciplinary including infantile urologist and endocrinologist. The prognosis in distal hypospadias is usually good following surgical repair, however in severe cases surgical interventions may be more challenging in order to obtain satisfactory outcome in terms of function and esthetic.

Whole exome sequencing analysis and prenatal diagnosis in children with neurodevelopmental disorders / 中华预防医学杂志

To explore the application value of whole exome sequencing (WES) in the diagnosis of prenatal and postnatal neurodevelopmental disorders (NDDs). A total of 70 patients diagnosed with NDDs who underwent WES at the Medical Genetics Center of the Maternal and Child Health Hospital of Hubei Province between June 2020 and July 2021 were retrospectively analyzed. Genomic DNA was extracted from peripheral blood samples and amniotic fluid. WES-based copy number variant (CNV) analysis was integrated into the routine WES data analysis pipeline. The results showed that a molecular diagnosis rate could be made in 21/70 (30%) cases. Of 21 positive cases, 14 (23%) cases were detected by single-nucleotide variant/small insertion/deletion (SNV/Indel) analysis, of which 12 variants were novel, 6 (9.8%) cases were detected by WES-based CNV analysis, and 1 (1.6%) case was detected by a combination of both. The diagnostic yield of WES combined with CNV analysis was higher than that of SNV/Indel analysis alone (30%, 21/70 vs. 20%, 14/70). Of the 28 prenatally diagnosed cases, 6 cases were found to have inherited parental variation for NDDs, 10 cases were found not to have the same pathogenic variation as the proband, and the remaining 12 cases were found to have no pathogenic or likely pathogenic variation that could explain the NDDs phenotype. Clinical follow-up showed that 5 families opted for abortion and the remaining had no current abnormalities. In conclusion, WES may be an effective method to clarify the genetic etiology and prenatal diagnosis of NDDs, which is helpful in assessing the prognosis to aid clinical management and reproductive guidance.

Prenatal diagnosis and genetic analysis of two cases of Turner syndrome due to isodicentric Xp11.22 / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of idic(X)(p11.22) in Turner syndrome (TS).@*METHODS@#Two fetuses suspected for sex chromosome abnormalities or ultrasound abnormalities were selected from Chengdu Women's and Children's Central Hospital in October 2020 and June 2020, and amniotic fluid samples were collected for G-banded chromosomal karyotyping analysis, chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH).@*RESULTS@#The two fetuses were respectively found to have a karyotype of 45,X[47]/46,X,psu idic(X)(p11.2)[53] and 46,X,psu idic(X)(p11.2). CMA found that both had deletions in the Xp22.33p11.22 region and duplications in the p11.22q28 region. FISH showed that the centromeres in both fetuses had located on an isochromosome.@*CONCLUSION@#The combination of karyotyping analysis, FISH, and CMA is useful for the delineation of complex structural chromosomal aberrations. High-resolution CMA can accurately identify chromosomal breakpoints, which can provide a clue for elucidating the mechanism of chromosomal breakage and rearrangement.

Carrier screening and prenatal diagnosis for thalassemia-associated mutations in Jiaxing area of Zhejiang / 中华医学遗传学杂志

OBJECTIVE@#To study the molecular epidemiology of thalassemia in Jiaxing area of Zhejiang province and provide a basis for prenatal diagnosis, genetic counseling and prevention and control of birth defects.@*METHODS@#A total of 24 003 pregnant women who presented at the Jiaxing Maternal and Child Health Care Hospital from April 2017 to September 2021 were enrolled. Capillary hemoglobin electrophoresis in combination with routine blood test were used for primary screening for carriers of thalassemia-associated mutations, and those with positive results were subjected to fluorescence quantitative PCR assay. Prenatal diagnosis was provided for couples with a risk of giving birth to children with intermediate or severe thalassemia.@*RESULTS@#Among the 24 003 pregnant women, 1 211 cases were suspected as carriers of thalassemia-associated mutations, among whom 443 (36.58%) were confirmed by genetic testing. Among these, carriers of α-, β- and α-complex β-globin gene mutations have accounted for 27.31% (121/443), 70.65% (313/443) and 2.04% (9/443), respectively. The result of prenatal diagnosis for an at-risk couple was --SEA/αCSα, and the fetus was predicted to have intermediate or severe thalassemia. Termination of the pregnancy was recommended.@*CONCLUSION@#Hemoglobin electrophoresis combined with routine blood test during pregnancy may be used as a preliminary screening measure for carriers of thalassemia-associated variants. Combined with genetic testing, this will be of great significance for the control of thalassemia in this region.

Analysis of a fetus with unbalanced translocation derived from a balanced t(6;14) maternal translocation / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a fetus with a high risk by maternal serum screening during the second trimester.@*METHODS@#Genetic counseling was provided to the pregnant woman on March 22, 2020 at Henan Provincial People's Hospital. G-banded chromosomal karyotyping and array comparative genomic hybridization (aCGH) were carried out on the amniotic fluid sample and peripheral blood samples from the couple.@*RESULTS@#The fetus and the pregnant woman were respectively found to have a 46,XX,der(6)t(6;14)(q27;q31.2) and 46,XX,t(6;14)(q27;q31.2) karyotype, whilst the husband was found to have a normal karyotype. aCGH analysis has identified a 6.64 Mb deletion at 6q26q27 and a 19.98 Mb duplication at 14q31.3q32.33 in the fetus, both of which were predicted to be pathogenic copy number variations. No copy number variation was found in the couple.@*CONCLUSION@#The unbalanced chromosome abnormalities in the fetus have probably derived from the balanced translocation carried by the pregnant woman. aCGH can help to determine the types of fetal chromosome abnormalities and site of chromosomal breakage, which may facilitate the prediction of fetal outcome and choice for subsequent pregnancies.

Value of chromosomal microarray analysis for the diagnosis of fetuses with anomalies of central nervous system / 中华医学遗传学杂志

OBJECTIVE@#To assess the value of chromosomal microarray analysis (CMA) for the diagnosis of fetuses with anomalies of the central nervous system (CNS) and summarize the outcome of the pregnancies and follow-up.@*METHODS@#A total of 636 fetuses from June 2014 to December 2020 who were referred to the Prenatal Diagnosis Center of Nanjing Drum Tower Hospital due to abnormal CNS prompted by ultrasound were selected as the research subjects. Based on the ultrasound findings, the fetuses were divided into ventricular dilatation group (n = 441), choroid plexus cyst group (n = 41), enlarged posterior fossa group (n = 42), holoprosencephaly group (n = 15), corpus callosum hypoplasia group (n = 22), and other anomaly group (n = 75). Meanwhile, they were also divided into isolated (n = 504) and non-isolated (n = 132) groups based on the presence of additional abnormalities. Prenatal samples (amniotic fluid/chorionic villi/umbilical cord blood) or abortus tissue were collected for the extraction of genomic DNA and CMA assay. Outcome of the pregnancies and postnatal follow-up were summarized and subjected to statistical analysis.@*RESULTS@#In total 636 fetuses with CNS anomalies (including 89 abortus tissues) were included, and 547 cases were followed up. The overall detection rate of CMA was 11.48% (73/636). The detection rates for the holoprosencephaly group, ACC group, choroid plexus cyst group, enlarged posterior fossa group, ventricular dilatation group and other anomaly group were 80% (12/15), 31.82% (7/22), 19.51% (8/41), 14.29% (6/42), 7.48% (33/441) and 9.33% (7/75), respectively. Compared with the isolated CNS anomaly group, the detection rate for the non-isolated CNS anomaly group was significantly higher (6.35% vs. 31.06%) (32/504 vs. 41/132) (χ² = 62.867, P < 0.001). Follow up showed that, for 52 fetuses with abnormal CMA results, 51 couples have opted induced labor, whilst 1 was delivered at full term with normal growth and development. Of the 434 fetuses with normal CMA results, 377 were delivered at full term (6 had developmental delay), and 57 couples had opted induced labor. The rate of adverse pregnancy outcome for non-isolated CNS abnormal fetuses was significantly higher than that of isolated CNS abnormal fetuses (26.56% vs. 10.54%) (17/64 vs. 39/370) (χ² = 12.463, P < 0.001).@*CONCLUSION@#Fetuses with CNS anomaly should be tested with CMA to determine the genetic cause. Most fetuses with negative CMA result have a good prognosis, but there is still a possibility for a abnormal neurological phenotype. Fetuses with CNS abnormalities in conjunct with other structural abnormalities are at increased risk for adverse pregnancy outcomes.

Clinical features and genetic analysis of a child with acute form of Tyrosinemia type I due to a novel variant of FAH gene / 中华医学遗传学杂志

OBJECTIVE@#To analyze the clinical phenotype and genetic basis for a child with acute form of tyrosinemia type I (TYRSN1).@*METHODS@#A child with TYRSN1 who presented at the Gansu Provincial Maternal and Child Health Care Hospital in October 2020 was selected as the subject. The child was subjected to tandem mass spectrometry (MS-MS) and urine gas chromatography-mass spectrometry (GC-MS) for the detection of inherited metabolic disorders, in addition with whole exome sequencing (WES). Candidate variants were validated by Sanger sequencing.@*RESULTS@#The child's clinical features included abdominal distension, hepatomegaly, anemia and tendency of bleeding. By mass spectrometry analysis, her serum and urine tyrosine and succinylacetone levels have both exceeded the normal ranges. WES and Sanger sequencing revealed that she has harbored c.1062+5G>A and c.943T>C (p.Cys315Arg) compound heterozygous variants of the FAH gene, which were inherited from her father and mother, respectively. Among these, the c.943T>C was unreported previously.@*CONCLUSION@#Considering her clinical phenotype and result of genetic testing, the child was diagnosed with TYRSN1 (acute type). The compound heterozygous variants of the FAH gene probably underlay the disease in this child. Above finding has further expanded the spectrum of FAH gene variants, and provided a basis for accurate treatment, genetic counseling and prenatal diagnosis for her family.

Clinical application and evaluation of health economics for non-invasive prenatal testing of fetuses in Tianjin / 中华医学遗传学杂志

OBJECTIVE@#To assess the clinical efficacy and health economic value of non-invasive prenatal testing (NIPT) for the prenatal screening of common fetal chromosomal aneuploidies.@*METHODS@#10 612 pregnant women from October 2017 to December 2019 presented at the antenatal screening clinic of the General Hospital of Tianjin Medical University were selected as the study subjects. Results of NIPT and invasive prenatal diagnosis and follow-up outcome for the 10 612 pregnant women were retrospectively analyzed and compared. Meanwhile, NIPT data for two periods were analyzed for assessing the health economic value of NIPT as the second- or first-tier screening strategy for the prenatal diagnosis of fetal trisomies 21, 18 and 13.@*RESULTS@#The NIPT was successful in 10 528 (99.72%) subjects, with the sensitivity for fetal trisomies 21, 18 and 13 being 100%, 92.86% and 100%, and the positive predictive value (PPV) being 89.74%, 61.90% and 44.44%, respectively. The PPV of NIPT for sex chromosome aneuploidies was 34.21%. Except for one false negative case of trisomy 18, the negative predictive value for trisomy 21, trisomy 13 and other chromosomal abnormalities were 100%. For pregnant women with high risk by serological screening, advanced maternal age or abnormal ultrasound soft markers, NIPT has yielded a significantly increased high risk ratio. There was no statistical difference in the PPV of NIPT among pregnant women from each subgroup. NIPT would have higher health economic value as a second-tier screening until 2019, while compared to 2015 ~ 2017, its incremental cost-effectiveness ratio as a first-tier screening had declined clearly.@*CONCLUSION@#The screening efficacy of NIPT for trisomies 21, 18 and 13 for a mixed population is significantly better than conventional serological screening, but it is relatively low for sex chromosomal abnormalities. NIPT can also be recommended for populations with relatively high risks along with detailed pre- and post-test genetic counselling. From the perspective of health economics, except for open neural tube defects, it is possible for NIPT to replace the conventional serological screening in the future as its cost continues to decrease.

Prenatal diagnosis for a fetus with 5p deletion syndrome / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a fetus with club foot detected upon mid-pregnancy ultrasonography.@*METHODS@#Amniotic fluid of the fetus and peripheral blood samples of its parents were collected and subjected to G-banding karyotype analysis and copy number variation sequencing (CNV-seq). The result was verified by fluorescence in situ hybridization (FISH).@*RESULTS@#The fetus and its parents all had a normal karyotype. CNV-seq analysis revealed that the fetus has harbored a 23.12 Mb on chromosome 5 and a 21.46 Mb duplication on chromosome 7. FISH assay has verified that its mother has carried a cryptic t(5;7)(p14.3;q33) translocation.@*CONCLUSION@#CNV-seq combined with FISH can effectively detect cryptic chromosome aberrations, and can help to reduce severe birth defects and provide a basis for prenatal genetic counseling.

Prenatal diagnosis and genetic analysis of a rare case with 8p deletion and duplication / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic etiology for a child featuring mental retardation, language delay and autism.@*METHODS@#G-banding chromosomal karyotyping and single nucleotide polymorphism array (SNP-array) were carried out for the child and her parents.@*RESULTS@#The child was found to have a 46,XX,dup(8p?) karyotype, for which both of her parents were normal. SNP-array revealed that the child has harbored a 6.8 Mb deletion in 8p23.3p23.1 and a 21.8 Mb duplication in 8p23.1p12, both of which were verified as de novo pathogenic copy number variants.@*CONCLUSION@#The clinical features of the child may be attributed to the 8p deletion and duplication. SNP-array can facilitate genetic diagnosis for children featuring mental retardation in conjunct with other developmental anomalies.

Application value of CNV-seq for the prenatal diagnosis of women with high-risk pregnancies / 中华医学遗传学杂志

OBJECTIVE@#To assess the application value of copy number variation sequencing (CNV-seq) for women with a high risk for fetal anomalies.@*METHODS@#Based on the results of non-invasive prenatal testing (NIPT), 271 high-risk pregnant women were divided into NIPT positive group (n = 83) and other anomaly group (advanced age, high risk by serological screening, repeated NIPT failure, adverse pregnancy history, abnormal ultrasound finding, and abnormal phenotype) (n = 188). CNV-seq was carried out to detect copy number variations (CNVs) in amniocytic DNA from the two groups of pregnant women, and karyotyping analysis of the amniotic cells was carried out for verification and comparison.@*RESULTS@#The amniocytes from 271 pregnant women were detected. The detection rate was 20.66% (56/271) for pathogenic CNVs by CNV-seq and 19.19% (52/271) for pathogenic karyotypes by karyotyping analysis. The difference was statistically significant (P < 0.05). CNV-seq had shown that, compared with NIPT positive group, the detection rates for likely pathogenic CNVs and variants of unknown significance (VUS) in other abnormality group were significantly higher [2.41%(2/83) vs. 5.32%(10/188)](P < 0.05).@*CONCLUSION@#CNV-seq can well suit the first-tier diagnosis for pregnant women suspected for fetal abnormality. In prenatal diagnosis settings, CNV-seq can identify additional and clinically significant cytogenetic abnormalities. In those with other abnormalities, the detection rates for likely pathogenic CNVs and VUS are higher than with the NIPT positive cases.

Genetics in prenatal diagnosis

The options for prenatal genetic testing have evolved rapidly in the past decade, and advances in sequencing technology now allow genetic diagnoses to be made down to the single-base-pair level, even before the birth of the child. This offers women the opportunity to obtain information regarding the foetus, thereby empowering them to make informed decisions about their pregnancy. As genetic testing becomes increasingly available to women, clinician knowledge and awareness of the options available to women is of great importance. Additionally, comprehensive pretest and posttest genetic counselling about the advantages, pitfalls and limitations of genetic testing should be provided to all women. This review article aims to cover the range of genetic tests currently available in prenatal screening and diagnosis, their current applications and limitations in clinical practice as well as what the future holds for prenatal genetics.