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.

Turner syndrome associated with Down syndrome: about a case / Síndrome Turner asociado a síndrome Down: a propósito de un caso

The coexistence of double aneuploidy of Down and Turner syndromes is rare; most cases have been due to double mitotic errors. The objective of the study was to report a case with monosomy of the X chromosome and trisomy of chromosome 21, in mosaic variety, highlighting the phenotypic effect that the presence of different chromosomal abnormalities can produce and compare with those reported in the literature. A 10-year-old Ecuadorian female, born to a multipregnant mother with 46 years at conception, is seen in consultation with a predominant clinical phenotype of Down syndrome, associated with menarche, presence of pubic and axillary villu, where a karyotype is verified 45 X[7]/47XX+ 21 [3]/46, X, der (X)(: p11.1-> q11.1)[1]/46,XX [1]. The present case is a double Turner-Down aneuploidy, with predominantly X monosomy cell line, who shows important mental retardation and some signs of puberal development not usually in Turner syndrome. These features highlight the clinical importance of doing a karyotype in mental retardation cases and searching low mosaics of another aneuploidies in atypical cases. Its complex chromosomal formula and support with molecular cytogenetics allowed diagnostic confirmation and genetic counseling.

La coexistencia de doble aneuploidía de los síndromes de Down y Turner es rara; la mayoría de los casos se han debido a dobles errores mitóticos. Reportar un caso con trisomía del cromosoma 21 y monosomía del cromosoma en X, en variedad mosaico, que curiosamente presenta un despertar puberal precoz y comparar con los reportados en la literatura. Paciente ecuatoriana de sexo femenino, de 10 años de edad, nacida de madre multigesta con 46 años a la concepción, que es vista en consulta con fenotipo clínico predominante de Síndrome Down, asociado a menarquia y telarquia, donde se constata un cariotipo. El presente caso es el primero informado de mosaicismo de doble aneuploidía de Turner-Down asociado con un despertar puberal precoz. Su fórmula cromosómica compleja y el apoyo con la citogenética molecular permitió la confirmación diagnostica y la asesoría genética.

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.

Preparation and evaluation of quality management samples for noninvasive prenatal screening / 中华医学遗传学杂志

OBJECTIVE@#To prepare a quality control sample for non-invasive prenatal screening (NIPS) and evaluate its quality and stability.@*METHODS@#According to the biological characteristics of cell-free fetal DNA derived from the plasma of pregnant women, the simulated samples were prepared by mixing genomic DNA fragments derived from individuals with trisomy 21, trisomy 18 and trisomy 13 and background plasma. The samples were then compared with commercially made quality control products tested on various NIPS platforms and stored at -80℃, -20℃, 4℃, 24℃ and 37℃ for various periods of time.@*RESULTS@#The simulated samples have attained the expected results and could be detected on various platforms and stored at -80℃and -20℃ for at least 30 days.@*CONCLUSION@#A simulated sample was successfully prepared and possessed good stability. It can be used as the quality control sample for NIPS.

Differential expression profile of miRNAs in amniotic fluid exosomes from fetuses with Down syndrome / 南方医科大学学报

OBJECTIVE@#To investigate the role of miRNAs in amniotic fluid exosomes in growth and development of fetuses with Down syndrome (DS).@*METHODS@#Amniotic fluid were collected from 20 fetuses with DS and 20 normal fetuses (control) to extract amniotic exosome miRNA. MicroRNA sequencing technique was used to identify the differentially expressed miRNAs between the two groups, for which gene ontology (GO) and pathway analysis was performed. Three differentially expressed miRNAs with the strongest correlation with DS phenotype were selected for qPCR verification. Dual luciferase reporter assay was used to verify the activity of let-7d-5p for targeted regulation of BACH1.@*RESULTS@#We identified 15 differentially expressed miRNAs in DS as compared with the control group, among which 7 miRNAs were up-regulated and 8 were down-regulated. Target gene prediction results showed that the differentially expressed miRNAs targeted 17 DS-related genes. GO analysis revealed that the main functions of the target genes involved protein binding, protein transport, ATP binding, transferase activity and synapses. Pathway analysis revealed that the functional pathways were closely related with the development of the nervous system. qPCR results showed that the expression levels of miR-140-3p and let-7d-5p were significantly lower in DS group than in the control group (P < 0.05), as was consistent with miRNA sequencing results; the expression level of miR-4512 was significantly higher in DS group than in control group (P < 0.05), which was contrary to miRNA sequencing results. The results of double luciferase reporter gene assay confirmed that let-7d-5p was capable of targeted regulation of BACH1 expression.@*CONCLUSION@#Let-7d-5p in amniotic fluid exosomes may promote oxidative stress events in the brain of fetuses with DS by regulating BACH1 expression.

Caracterización de pacientes con enfermedades genéticas / Characterization of Patients with Genetic Diseases

Introducción: Las enfermedades genéticas se corresponden con variaciones genéticas del desarrollo que precisan ayuda médica, educativa, social o combinaciones de estas. Objetivo: Caracterizar clínica y epidemiológicamente a los pacientes con enfermedades genéticas. Método: Estudio descriptivo transversal. El universo estuvo constituido por los 521 pacientes evaluados en la consulta de asesoramiento genético del municipio Mayarí y la muestra estuvo representada por los 216 pacientes portadores de enfermedades genéticas pertenecientes al Policlínico Universitario 26 de Julio; del Área de Salud de Mayarí, durante el año 2018. Resultados: Predominó el sexo femenino (53,24 por ciento), el grupo de edades de 41 a 50 años (18,06 por ciento), las enfermedades monogénicas (58,8 por ciento), los pacientes con síndrome de Down (20,37 por ciento), los pacientes que no cuentan con antecedentes familiares (54,63por ciento). Conclusiones: Prevalecieron los pacientes con discapacidad mental, con diagnóstico posnatal y con más de 20 años de diagnóstico. El mayor número no realizaba tratamiento. Los pacientes vinculados integralmente a la sociedad resultaron minoría, así como los que tenían antecedentes familiares de enfermedad genética(AU)

Introduction: Genetic diseases are due to developmental genetic variations that require medical, educational and social help, or combinations of these. Objective: To characterize, clinically and epidemiologically, patients with genetic diseases. Method: Descriptive and cross-sectional study. The universe was made up of the 521 patients assessed in the genetic counseling consultation of Mayarí Municipality and the sample was represented by the 216 patients with genetic diseases belonging to 26 de Julio University Polyclinic of the health area of Mayarí, during the year 2018. Results: The female sex predominated (53.24 percent), together with the age group 41-50 years (18.06 percent), monogenic diseases (58.8 percent), patients with Down syndrome (20.37 percent), and patients with no family history of diseases (54.63 percent). Conclusions: Patients with mental disabilities, with postnatal diagnosis and with more than twenty years of diagnosis prevailed. The largest number did not undergo treatment. Patients fully linked to society were a minority, as well as those with a family history of genetic disease(AU)

Analysis of the results of chromosomal trisomies 21, 18 and 13 screening among 40 628 women by non-invasive prenatal testing / 中华医学遗传学杂志

OBJECTIVE@#To assess the clinical value of non-invasive prenatal testing (NIPT) for the screening of trisomy and copy number variations (CNVs) of chromosomes 21, 18 and 13.@*METHODS@#From January 2015 to December 2019, 40 628 pregnant women underwent NIPT testing using high-throughput sequencing and bioinformatics analysis to test the cell-free fetal DNA in maternal plasma. High-risk pregnant women underwent invasive prenatal diagnosis, while low-risk ones were followed up by telephone.@*RESULTS@#The three most common indications included intermediate risk of serological screening, high risk of serological screening and advanced maternal age. Among all pregnant women, 257 cases were detected as trisomy 21, 18 and 13 (170, 49 and 38 cases, respectively). 227 cases chose invasive prenatal diagnosis, with respectively 122, 28 and 10 cases confirmed. The positive predictive value (PPV) was 81.33% (122/150), 65.12% (28/43), 29.41% (10/34), respectively. Two false negative cases of trisomy 18 were found during follow-up. Meanwhile, NIPT has detected 46 cases (15, 16 and 15 cases, respectively) CNVs on chromosomes 21, 18 and 13, among which 37 cases underwent invasive prenatal diagnosis. There were 5, 3 and 5 positive cases, which yielded a PPV of 41.67% (5/12), 25%(3/12) and 33.33%(5/15), respectively. Two other chromosome CNVs were accidentally discovered among the false positive samples.@*CONCLUSION@#The incidence of chromosomal abnormalities in the serological screening high-risk group was 52.02%, which was significantly higher than other groups. NIPT has a high sensitivity and specificity for the screening of trisomies 21, 18 and 13, while its accuracy for detecting CNVs of chromosomes 21, 18 and 13 needs to be improved. As a screening method, NIPT has a great clinical value, though there are still limitations of false positive and false negative results.Comprehensive pre- and post-test genetic counseling should be provided to the patients.

Clinical effect of expanded non-invasive prenatal testing for serological screening of fetuses with high-risk for Down's syndrome / 中华医学遗传学杂志

OBJECTIVE@#To investigate the clinical effect of expanded non-invasive prenatal testing (NIPT-plus) for serological screening of fetuses with high-risk for Down's syndrome.@*METHODS@#To retrospectively study the screening results, prenatal diagnosis and pregnancy outcomes of 1561 midterm pregnant women underwent NIPT-plus in our center from September 2018 to December 2019 due to serological screening with high-risk for Down's syndrome(≥ 1/270).@*RESULTS@#45 pregnant women had a high-risk with a detection rate of 2.88% (45/1561) of 1561 pregnant women who performed NIPT-plus. 40 pregnant women underwent invasive prenatal diagnosis and 20 cases were confirmed with a positive predictive value of 50.0% (20/40). Statistical analysis showed that NIPT-plus has a high detection rate for trisomy 21, sex chromosomal aneuploidy, and MMS in the 0.1/90 group, but with a positive predictive value lower than the other two groups.@*CONCLUSION@#The detection rate and PPVs of NIPT-plus in different groups of Down's high-risk pregnant women was different. NIPT-plus can reduce the pressure of prenatal diagnosis and can be used as a screening method for Down's syndrome with high risk in pregnant women.

Genome-wide analysis of aberrant DNA methylation patterns in iPSCs derived from patients with Down syndrome / 中华医学遗传学杂志

OBJECTIVE@#To study the correlation between DNA methylation patterns and gene expression in Down syndrome (DS).@*METHODS@#Induced pluripotent stem cells (iPSCs) derived from normal controls and DS patients were subjected to whole genome bisulfite sequencing and differentially methylated region (DMR) screening. Statistical analysis for chromosomal and gene element distribution were carried out for DMR. Gene ontology (GO) and enrichment-based cluster analysis were used to explore the molecular function of differentially expressed genes.@*RESULTS@#A total of 1569 DMR were identified in iPSCs derived from DS patients, for which the proportion of hypermethylation in promoter regions was significantly greater than that of the genebody. No DMR enrichment was noted on chromosome 21. Hypermethylation of the promoter and genebody was predicted to be inhibitory for gene expression. Functional clustering revealed the pathways related to neurodevelopmental, stem cell pluripotency and organ size regulation to be significantly correlated with differentially methylated genes.@*CONCLUSION@#Extensive and stochastic anomalies of genome-wide DNA methylation has been discovered in iPSCs derived from DS patients, for which the pattern and molecular regulation of methylation were significantly different from those of normal controls. Above findings suggested that DNA methylation pattern may play a vital role in both the pathogenesis of neurodevelopmental disorders and other phenotypic abnormalities during early embryonic development.

Analysis of the efficacy of non-invasive prenatal testing in the system of prenatal screening and diagnosis / 中华医学遗传学杂志

OBJECTIVE@#To evaluate the efficacy of non-invasive prenatal testing (NIPT) in the prenatal screening and its role in the system of prenatal diagnosis.@*METHODS@#A total of 22 649 singleton pregnant women who were registered and finally delivered or had induced labor at Beijing Obstetrics and Gynecology Hospital of Capital Medical University were enrolled. The routes of prenatal screening were analyzed to evaluate the efficacy of prenatal screening. Meanwhile, 9268 pregnant women who underwent invasive prenatal diagnosis procedure were enrolled. The indications and results of prenatal diagnosis were analyzed to evaluate the effectiveness of prenatal screening.@*RESULTS@#60.24% of singleton pregnant women have opted for Down syndrome screening, and their age was mainly under 35. The proportion of women opted for NIPT was 34.74%, and were mainly between 35 and 39. The overall diagnostic rate of trisomy 21, 18 and 13 trisomy for those with high risk by NIPT was 0.89%, which yielded a positive predictive value of 75.71%. For those with moderate risk by serum screening, 0.30% was predicted with a high risk by NIPT. Among women undergoing prenatal diagnosis, 63.04% and 21.22% had the indication of advanced age or high risk by serum screening, and the positive predictive values were 5.1% and 5.13%, respectively. By contrast, 2.30% of women undergoing prenatal diagnosis had a high risk by NIPT, which yielded a positive predictive value of 54.46%.@*CONCLUSION@#With the change of the age composition of pregnant women and increase in the complexity of pregnancy in China, to build a prenatal screening system based on NIPT will be helpful to improve the efficiency of the current system of prenatal screening and diagnosis.

Rol de los marcadores ecográficos secundarios de primer trimestre para la detección de trisomía 21 / Role of first trimester secondary ultrasound markers for trisomy 21 detection

OBJETIVO: Analizar los resultados de los marcadores ecográficos secundarios (hueso nasal, onda a del ductus venoso y regurgitación tricuspídea) y valorar su efectividad para la detección de trisomía 21 y su utilidad para la reducción del número de pruebas invasivas. MÉTODOS: Tras la realización del test combinado de primer trimestre a toda paciente con un riesgo entre 1/101-1/1000 se realizó la valoración de los marcadores secundarios. RESULTADOS: Desde Enero de 2014 a Mayo de 2015 se realizaron 2.660 test combinados del primer trimestre valorándose la edad materna, la traslucencia nucal y la PAPP-A y ßhCG, teniendo una sensibilidad del 90% y una tasa de falsos positivos del 3,2%. Hubo 10 fetos con trisomía 21. La sensibilidad de hueso nasal, ductus venoso y regurgitación tricuspídea fue del 22,2%, 50% y 50% y la especificidad del 99,8%, 96,9% y 98,8% respectivamente. La sensibilidad global del test contingente fue del 90%, con una reducción de la tasa de falsos positivos al 1,6%, lo que se reduciría de 171 a 148 el número de amniocentesis. CONCLUSIÓN: El test contingente es una buena herramienta para reducir la tasa de falsos positivos respecto al test combinado sin disminuir la tasa de detección y con ello reducir la tasa de pruebas invasivas.

AIMS: To analyze the results of the secondary sonographic markers (nasal bone, wave ductus venosus and tricuspid regurgitation) and evaluate its effectiveness for the detection of trisomy 21 and thus reduce the number of invasive tests. METHODS: After completing the first trimester combined test, all patients with a risk between 1/101-1/1000 were evaluated the secondary sonographic markers. RESULTS: From January 2014 to May 2015 2660 combined test being assessed maternal age, nuchal translucency and PAPP-A and ßhCG were performed, with a sensitivity of 90% and a false positive rate of 3.2%. 10 fetuses with trisomy 21 were observed. The sensitivity of nasal bone, ductus venosus and tricuspid regurgitation was 22.2%, 50% and 50% and specificity was 99.8%, 96.9% and 98.8% respectively. The overall sensitivity of contingent test was 90%, with a reduction in false positive rate to 1.6%, which would decrease the number of amniocentesis from 171 to 148. CONCLUSION: The contingent test is a good tool to reduce the rate of false positives with respect to the combined test without decreasing the detection rate and thereby reduce the rate of invasive testing.

Teoria da mente em pais de pessoas com autismo: uma análise comparativa / Theory of mind for parents of people with autism: a comparative analysis

O autismo pode ser definido como uma síndrome comportamental heterogênea em termos genéticos e de diagnóstico. Esta heterogeneidade dificulta a realização de estudos genéticos sobre o tema. Um dos endofenótipos candidatos do autismo é a teoria da mente. O objetivo deste estudo foi avaliar a capacidade da teoria da mente em pais de crianças com autismo. Foram avaliados 90 participantes: 30 pais de crianças com autismo, 30 pais de crianças com síndrome de Down e 30 pais de crianças com desenvolvimento típico. Os instrumentos utilizados foram o Eyes Test, para avaliar habilidades de decodificação, e o Unexpected Outcomes Task, para medir o raciocínio dedutivo. Os resultados não indicam diferenças significativas entre os grupos na habilidade de decodificação. No entanto, eles indicam a existência de déficits na capacidade de dedução da teoria da mente. Esse déficit parece ser mais pronunciado em mães de crianças com autismo, em comparação com grupos de mães de crianças com síndrome de Down e mães de crianças com desenvolvimento típico. Mais estudos são necessários para esclarecer melhor a relação entre teoria da mente e autismo. (AU)

Autism can be defined as a heterogeneous behavioral syndrome in both genetic and diagnostic terms. This heterogeneity poses difficulties in conducting genetic studies on the topic. A candidate endophenotype of autism is theory of mind. The goal of this study was to evaluate the ability of theory of mind in parents of children with autism. We evaluated 90 participants: 30 parents of children with autism, 30 parents of children with Down syndrome and 30 parents of typically developing children. The instruments used were the Eyes Test, to assess decoding skills, and the Unexpected Outcomes Task, to measure deductive reasoning. The results do not indicate significant differences between groups in theory of mind decoding. However, they indicate the existence of deficits in the theory of mind reasoning. These deficits seem to be more pronounced in mothers of children with autism, compared to groups of mothers of children with Down syndrome and mothers of typically developing children. Further studies are needed to better clarify the relationship between theory of mind and autism. (AU)

Global differential expression of genes located in the Down Syndrome Critical Region in normal human brain / Expresión diferencial global de genes localizados en la Región Crítica del Síndrome de Down en el cerebro humano normal

Background: The information of gene expression obtained from databases, have made possible the extraction and analysis of data related with several molecular processes involving not only in brain homeostasis but its disruption in some neuropathologies; principally in Down syndrome and the Alzheimer disease. Objective: To correlate the levels of transcription of 19 genes located in the Down Syndrome Critical Region (DSCR) with their expression in several substructures of normal human brain. Methods: There were obtained expression profiles of 19 DSCR genes in 42 brain substructures, from gene expression values available at the database of the human brain of the Brain Atlas of the Allen Institute for Brain Sciences", (http://human.brain-map.org/). The co-expression patterns of DSCR genes in brain were calculated by using multivariate statistical methods. Results: Highest levels of gene expression were registered at caudate nucleus, nucleus accumbens and putamen among central areas of cerebral cortex. Increased expression levels of RCAN1 that encode by a protein involved in signal transduction process of the CNS were recorded for PCP4 that participates in the binding to calmodulin and TTC3; a protein that is associated with differentiation of neurons. That previously identified brain structures play a crucial role in the learning process, in different class of memory and in motor skills. Conclusion: The precise regulation of DSCR gene expression is crucial to maintain the brain homeostasis, especially in those areas with high levels of gene expression associated with a remarkable process of learning and cognition.

Introducción: La información de la expresión de genes consignada en bases de datos, ha permitido extraer y analizar información acerca procesos moleculares implicados tanto en la homeostasis cerebral y su alteración en algunas neuropatologías. Objetivos: Correlacionar los niveles de transcripción de 19 genes localizados en la región crítica del cromosoma 21, asociada a Síndrome de Down (DSCR), con la localización cerebral y su coexpresión en diferentes subestructuras del cerebro humano. Métodos: A partir de valores de expresión génica disponibles en la base de datos del proyecto cerebro humano del Atlas del Cerebro del "Allen Institute for Brain Sciences" (http://human.brain-map.org/), se construyeron perfiles de expresión de 19 genes DSCR en 42 subestructuras cerebrales. Además, utilizando métodos estadísticos multivariados se analizaron los patrones de coexpresión de genes DSCR en el cerebro normal. Resultados: En el núcleo caudado, el núcleo accumbens y el putamen además de las Áreas centrales 2, 3 y 4, se determinaron los valores de expresión más elevados para los genes incluidos RCAN1, que codifica para una proteína involucrada en el proceso de transducción de señales de SNC; PCP4 cuya proteína interviene en la unión a la calmodulina y TTC3 una proteína que interviene en la diferenciación de neuronas. Las subestructuras identificadas con una elevada expresión de estos genes, están asociadas con procesos de aprendizaje, en diferentes tipos de memoria y habilidades motoras. Conclusiones: La regulación de la expresión de los genes DSCR es clave para mantener la homeostasis cerebral, especialmente en aquellas áreas de mayor expresión, las cuales están asociadas con procesos sumamente importantes.

Bioinformatics analysis of biomarkers and transcriptional factor motifs in Down syndrome

In this study, biomarkers and transcriptional factor motifs were identified in order to investigate the etiology and phenotypic severity of Down syndrome. GSE 1281, GSE 1611, and GSE 5390 were downloaded from the gene expression ominibus (GEO). A robust multiarray analysis (RMA) algorithm was applied to detect differentially expressed genes (DEGs). In order to screen for biological pathways and to interrogate the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database, the database for annotation, visualization, and integrated discovery (DAVID) was used to carry out a gene ontology (GO) function enrichment for DEGs. Finally, a transcriptional regulatory network was constructed, and a hypergeometric distribution test was applied to select for significantly enriched transcriptional factor motifs. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were each up-regulated two-fold in Down syndrome samples compared to normal samples; of these, SON and TTC3 were newly reported. CBR1, DYRK1A, HMGN1, ITSN1, RCAN1, SON, TMEM50B, and TTC3 were located on human chromosome 21 (mouse chromosome 16). The DEGs were significantly enriched in macromolecular complex subunit organization and focal adhesion pathways. Eleven significantly enriched transcription factor motifs (PAX5, EGR1, XBP1, SREBP1, OLF1, MZF1, NFY, NFKAPPAB, MYCMAX, NFE2, and RP58) were identified. The DEGs and transcription factor motifs identified in our study provide biomarkers for the understanding of Down syndrome pathogenesis and progression.

Down syndrome passed from mother to child / Transmisión de síndrome de Down de madre a hijo

Down syndrome is the leading cause of inherited intellectual disability; it is characterized by mental retardation associated to physical growth delay and certain physical traits or features. It is caused by the presence of a third copy of chromosome 21, being this trisomy the most common chromosomal aneuploidy. Women with Down syndrome are less fertile, and pregnancy in these women is rare, although the information on exact statistics of reproduction in these patients is very limited, and they often have difficulties with miscarriage, premature birth, and difficult labor. We report the case of a preterm newborn with Down syndrome passed from her mother; this pregnancy was a result of sexual assault, which is an event that can and should be prevented in this population.

El síndrome de Down es la principal causa de discapacidad intelectual congénita; se caracteriza por retraso mental asociado a retardo del crecimiento y del desarrollo psicomotor, así como a algunas características físicas típicas. Se debe a la presencia de una tercera copia del cromosoma 21, siendo esta trisomía la aneuploidía cromosómica más común. Las mujeres con síndrome de Down tienden a ser menos fértiles y el embarazo en ellas es poco frecuente, aunque los datos estadísticos de este evento son limitados, y se asocia, además, a dificultades que terminan en aborto, parto prematuro y parto difícil. Se reporta el caso de un recién nacido prematuro con síndrome de Down, hijo de madre con el mismo diagnóstico, producto de un embarazo resultado de violación, evento que debe ser prevenido de forma oportuna en esta población de alto riesgo.

Characterization of a rare short arm heteromorphism of chromosome 22 in a girl with down-syndrome like facies.

Chromosomal heteromorphisms are described as interindividual variation of chromosomes without phenotypic consequence. Chromosomal polymorphisms detected include most regions of heterochromatin of chromosomes 1, 9, 16 and Y and the short arms of all acrocentric chromosomes. Here, we report a girl with Down‑syndrome such as facies and tremendously enlarged short arm of a chromosome 22. Fluorescence in situ hybridization (FISH) with a probe specific for all acrocentric short arms revealed that the enlargement p arms of the chromosome 22 in question contained exclusively heterochromatic material derived from an acrocentric short arm. Parental studies identified a maternal origin of this heteromorphism. Cryptic trisomy 21 of the Down‑syndrome critical region was excluded by a corresponding FISH‑probe. Here, we report, to the best of our knowledge, largest ever seen chromosome 22 short arm, being ~×1.5 larger than the normal long arm.

Anormalidades cromossômicas entre pacientes com cardiopatia congênita / Chromosomal abnormalities in patients with congenital heart disease

FUNDAMENTO: As anormalidades cromossômicas (ACs) representam importante causa de cardiopatia congênita (CC). OBJETIVO: Determinar a frequência, os tipos e as características clínicas de ACs identificadas em uma amostra prospectiva e consecutiva de pacientes com CC. MÉTODO: Nossa amostra foi composta por pacientes com CC avaliados em sua primeira hospitalização em uma unidade cardíaca de tratamento intensivo de um hospital pediátrico de referência do sul do Brasil. Todos os pacientes foram submetidos à avaliação clínica e citogenética, através do cariótipo de alta resolução. Os defeitos cardíacos foram classificados segundo Botto e cols. Na análise estatística utilizou-se o qui-quadrado, o teste exato de Fisher e odds ratio (p < 0,05). RESULTADOS: Nossa amostra foi composta de 298 pacientes, 53,4% do sexo masculino, com idades variando de um dia a 14 anos. Anormalidades cromossômicas foram observadas em 50 pacientes (16,8%), sendo que 49 deles eram sindrômicos. Quanto às ACs, 44 delas (88%) eram numéricas (40 pacientes com +21, dois com +18, um com triplo X e um com 45,X) e seis (12%) estruturais [dois pacientes com der(14;21), +21, um com i(21q), um com dup(17p), um com del(6p) e um com add(18p)]. O grupo de CCs mais associado a ACs foi o do defeito de septo atrioventricular. CONCLUSÕES: ACs detectadas pelo cariótipo são frequentes entre pacientes com CC. Assim, os profissionais - especialmente aqueles que trabalham em serviços de cardiologia pediátrica - devem estar cientes das implicações que a realização do cariótipo pode trazer, tanto para o diagnóstico, tratamento e prognóstico desses pacientes como para o seu aconselhamento genético.

BACKGROUND: Chromosomal abnormalities (CAs) are an important cause of congenital heart disease (CHD). OBJECTIVE: Determine the frequency, types and clinical characteristics of CAs identified in a sample of prospective and consecutive patients with CHD. METHOD: Our sample consisted of patients with CHD evaluated during their first hospitalization in a cardiac intensive care unit of a pediatric referral hospital in Southern Brazil. All patients underwent clinical and cytogenetic assessment through high-resolution karyotype. CHDs were classified according to Botto et al. Chi-square, Fisher exact test and odds ratio were used in the statistical analysis (p < 0.05). RESULTS: Our sample consisted of 298 patients, 53.4% males, with age ranging from 1 day to 14 years. CAs were observed in 50 patients (16.8%), and 49 of them were syndromic. As for the CAs, 44 (88%) were numeric (40 patients with +21, 2 with +18, 1 with triple X and one with 45,X) and 6 (12%) structural [2 patients with der(14,21), +21, 1 with i(21q), 1 with dup(17p), 1 with del(6p) and 1 with add(18p)]. The group of CHDs more often associated with CAs was atrioventricular septal defect. CONCLUSIONS: CAs detected through karyotyping are frequent in patients with CHD. Thus, professionals, especially those working in Pediatric Cardiology Services, must be aware of the implications that performing the karyotype can bring to the diagnosis, treatment and prognosis and for genetic counseling of patients and families.

Caracterización de mutaciones en el gen GATA-1 en pacientes con Síndrome de Down y diagnóstico de mielopoyesis anormal transitoria o leucemia megacarioblástica aguda / Mutation characterization in the GATA-1 gene in patients with Down's Syndrome diagnosed with transient abnormal myelopoiesis or acute megakaryoblastic leukemia

Los pacientes con síndrome de Down tienen un riesgo más elevado de presentar leucemia megacarioblástica aguda (LMCA). Un 10% de los recién nacidos con ese síndrome presentan un cuadro de mielopoyesis anormal transitoria (MAT), indistinguible de la LMCA, que en general remite espontáneamente. En ambos grupos de pacientes se describió una alta incidencia de mutaciones en el gen GATA-1. Se analizaron 14 muestras de ADN de médula ósea (10 MAT/4 LMCA) correspondientes a 13 pacientes con Síndrome de Down mediante PCR y secuenciación, para describir la frecuencia y las características de las mutaciones en el gen GATA-1 en la población estudiada y sus consecuencias a nivel proteico. Se detectaron mutaciones en 10 de 10 MAT y en 3 de 4 LMCA, que a nivel proteico originarían un codón de terminación prematuro (n= 5), alteraciones en el sitio de corte y empalme (splicing) (n= 6) o cambio de secuencia (n= 3). Se confrmó la alta frecuencia de mutaciones en el gen GATA-1 en recién nacidos con Síndrome de Down y MAT o LMCA.

Patients with Down's Syndrome have a higher risk of developing acute megakaryoblastic leukemia (AML). Ten per cent of newborn infants with this syndrome have transient abnormal myelopoiesis (TAM), indistinguishable from AML, which generally remits spontaneously. A high incidence of GATA-1 gene mutations was described in both groups of patients. Fourteen bone marrow DNA samples (10 ATM/4 AML) were analyzed by PCR and sequencing; these samples were obtained from 13 patients with Down's Syndrome to describe the rate and mutation characteristics of the GATA-1 gene in the studied population and its consequences at a protein level. Mutations were detected in 10 out of 10 TAM and in 3 out of 4 AML, which at a protein level would result in an early termination codon (n= 5), alterations in the splicing site (n= 6) or sequence change (n= 3). The high rate of GATA-1 gene mutations was confirmed in newborn infants with Down's Syndrome and MAT or AML.

Prevalence of methylenetetrahydrofolate reductase 677 C-T polymorphism among mothers of Down syndrome children.

INTRODUCTION: The relationship between chromosomal non‑disjunction leading to aneuploidy and folate metabolism has drawn attention in the recent years. In this study, we examined the polymorphism in the gene encoding the folate metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR), namely, 677 C‑T in women having Down syndrome (DS) children. MATERIALS AND METHODS: The prevalence of these variant genotypes (MTHFR 677 C‑T polymorphism) in women having DS children (case mothers) (n = 110) was compared with controls (n = 111) from Punjab. Genotyping was done using the polymerase chain reaction method followed by restriction fragment length polymorphism. RESULTS: In the present study, 1.8% of case mothers had TT genotype while none of the control mothers showed this genotype. T allele frequency among cases was 0.13 and 0.11 in controls. The Chi‑square value showed a non‑significant difference between cases and controls. CONCLUSION: No association has been observed between 677 C‑T polymorphism and risk of non‑disjunction in case mothers. Detection of polymorphisms in more genes of folate pathway is required to find out the exact cause of non‑disjunction.