scholarly journals Prenatal Evaluation of MicroRNA Expressions in Pregnancies with Down Syndrome

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Biray Erturk ◽  
Emin Karaca ◽  
Ayca Aykut ◽  
Burak Durmaz ◽  
Ahmet Guler ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Chromosome 21 ◽  
Screening Tests ◽  
Sonographic Examination ◽  
Noninvasive Prenatal Testing ◽  
Abnormal Finding ◽  
Expression Levels ◽  
Increased Risk

Background. Currently, the data available on the utility of miRNAs in noninvasive prenatal testing is insufficient in the literature. We evaluated the expression levels of 14 miRNAs located on chromosome 21 in maternal plasma and their utility in noninvasive prenatal testing of Down Syndrome.Method. A total of 56 patients underwent invasive prenatal testing; 23 cases were carrying Down Syndrome affected fetuses, and 33 control cases carrying unaffected, normal karyotype fetuses were included for comparison. Indications for invasive prenatal testing were advanced maternal age, increased risk of Down Syndrome in screening tests, and abnormal finding in the sonographic examination. In both the study and control groups, all the pregnant women were at 17th and 18th week of gestation. miRNA expression levels were measured using real-time RT-PCR.Results. Significantly increased maternal plasma levels of miR-3156 and miR-99a were found in the women carrying a fetus with Down Syndrome.Conclusion. Our results provide a basis for multicenter studies with larger sample groups and microRNA profiles, particularly with the microRNAs which were found to be variably expressed in our study. Through this clinical research, the utility of microRNAs in noninvasive prenatal testing can be better explored in future studies.

Parenting the Child With Down Syndrome: Understanding—but Going Beyond—the “Down Syndrome Advantage”

2020 ◽  
Author(s):  
Robert M. Hodapp ◽  
Ellen G. Casale
Keyword(s):  
Socioeconomic Status ◽  
Down Syndrome ◽  
Behavior Problems ◽  
Prenatal Testing ◽  
Children With Autism ◽  
Facial Features ◽  
Cultural Resources ◽  
Noninvasive Prenatal Testing ◽  
Birth Parents ◽  
Children With Down Syndrome

Compared to parents of children with other types of intellectual disabilities, parents of children with Down syndrome experience less stress and more rewards, although this “Down syndrome advantage” mostly occurs compared to parents of children with autism and before groups are equated. Behaviorally, children with Down syndrome display more sociable interactional styles and baby-faced facial features, along with fewer instances of severe behavior problems. Demographically, parents of children with (versus without) Down syndrome average 5 years older when giving birth; parents are more often well educated, married, of higher socioeconomic status, and they likely provide these children greater financial and cultural resources. In most industrialized societies, rates of Down syndrome seem steady, with easily available, noninvasive prenatal testing counteracted by increasing numbers of women giving birth at older ages. Parenting children with Down syndrome relates to characteristics of children, their parents, and society, all of which intersect in important, underexplored ways.

scholarly journals A prenatal diagnosis case of partial duplication 21q21.1-q21.2 with normal phenotype maternally inherited

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Chunyan Jin ◽  
Zhiping Gu ◽  
Xiaohan Jiang ◽  
Pei Yu ◽  
Tianhui Xu
Keyword(s):  
Down Syndrome ◽  
Pregnant Woman ◽  
Prenatal Testing ◽  
Chromosome 21 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Serological Screening ◽  
Partial Duplication ◽  
Her Family ◽  
Clinical Consequences

Abstract Background Down syndrome is characterized by trisomy 21 or partial duplication of chromosome 21. Extensive studies have focused on the identification of the Down Syndrome Critical Region (DSCR). We aim to provide evidence that duplication of 21q21.1-q21.2 should not be included in the DSCR and it has no clinical consequences on the phenotype. Case presentation Because serological screening was not performed at the appropriate gestational age, noninvasive prenatal testing (NIPT) analysis was performed for a pregnant woman with normal prenatal examinations at 22 weeks of gestation. The NIPT results revealed a 5.8 Mb maternally inherited duplication of 21q21.1-q21.2. To assess whether the fetus also carried this duplication, ultrasound-guided amniocentesis was conducted, and the result of chromosomal microarray analysis (CMA) with amniotic fluid showed a 6.7 Mb duplication of 21q21.1-q21.2 (ranging from position 18,981,715 to 25,707,009). This partial duplication of 21q21.1-q21.2 in the fetus was maternally inherited. After genetic counseling, the pregnant woman and her family decided to continue the pregnancy. Conclusion Our case clearly indicates that 21q21.1-q21.2 duplication is not included in the DSCR and most likely has no clinical consequences on phenotype.

Efficiency of Noninvasive Prenatal Testing for Sex Chromosome Aneuploidies

2021 ◽  
pp. 1-9
Author(s):  
Yunfang Shi ◽  
Xiaozhou Li ◽  
Duan Ju ◽  
Yan Li ◽  
Xiuling Zhang ◽  
...  
Keyword(s):  
Screening Tool ◽  
Sex Chromosome ◽  
Diagnostic Testing ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Chromosome Abnormalities ◽  
Noninvasive Prenatal Testing ◽  
Sex Chromosome Abnormalities ◽  
Sex Chromosome Aneuploidies ◽  
Mosaic Karyotype

<b><i>Objective:</i></b> This study was designed to investigate the efficiency of noninvasive prenatal testing (NIPT) for screening fetal sex chromosome aneuploidies (SCAs) through sequencing of cell-free DNA in maternal plasma. <b><i>Methods:</i></b> This is a retrospective study on the positive NIPT results for SCAs collected from our hospital between January 2012 and December 2018. Samples with positive NIPT results for SCAs were then confirmed by prenatal or postnatal karyotyping analysis. <b><i>Results:</i></b> After cytogenetic analysis, abnormal karyotypes were confirmed in 104 cases and the overall positive predictive value (PPV) of NIPT for SCAs was 43.40% (102/235). The most frequently detected karyotypes included 47,XXY (<i>n</i> = 42), 47,XXX (<i>n</i> = 20), 47,XYY (<i>n</i> = 16), and 45,X (<i>n</i> = 2). Meanwhile, 10 cases were confirmed with mosaic karyotype 45,X/46,XX and 14 cases with numerical or structural chromosome abnormalities, including a double trisomy 48,XXX,+18. Cytogenetic results from the other 131 cases showed normal XX or XY, which were discordant with NIPT results. Upon analysis of parental karyotypes, 29 (12.34%) showed false positivity in NIPT results that were caused by maternal sex chromosome abnormalities. <b><i>Conclusion:</i></b> NIPT is an effective screening tool for SCA with a PPV of 43.40%. Maternal karyotype abnormalities occurred in 12.34% of the cases with abnormal NIPT. Diagnostic testing of the fetus and the mother are recommended.

scholarly journals Intracerebral haemorrhage in Down syndrome: protected or predisposed?

F1000Research ◽  
2016 ◽  
Vol 5 ◽  
pp. 876 ◽  
Author(s):  
Lewis Buss ◽  
Elizabeth Fisher ◽  
John Hardy ◽  
Dean Nizetic ◽  
Jurgen Groet ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Intracerebral Haemorrhage ◽  
Early Onset ◽  
Epidemiological Data ◽  
Haemorrhagic Stroke ◽  
Brain Parenchyma ◽  
Chromosome 21 ◽  
Clinical Consequence ◽  
Increased Risk ◽  
The Central Nervous System

Down syndrome (DS), which arises from trisomy of chromosome 21, is associated with deposition of large amounts of amyloid within the central nervous system. Amyloid accumulates in two compartments: as plaques within the brain parenchyma and in vessel walls of the cerebral microvasculature. The parenchymal plaque amyloid is thought to result in an early onsetAlzheimer’s disease (AD) dementia, a phenomenon so common amongst people with DS that it could be considered a defining feature of the condition. The amyloid precursor protein (APP) gene lies on chromosome 21 and its presence in three copies in DS is thought to largely drive the early onset AD. In contrast, intracerebral haemorrhage (ICH), the main clinical consequence of vascular amyloidosis, is a more poorly defined feature of DS. We review recent epidemiological data on stroke (including haemorrhagic stroke) in order to make comparisons with a rare form of familial AD due to duplication (i.e. having three copies) of the APP region on chromosome 21, here called ‘dup-APP’, which is associated with more frequent and severe ICH. We conclude that although people with DS are at increased risk of ICH, this is less common than in dup-APP, suggesting the presence of mechanisms that act protectively. We review these mechanisms and consider comparative research into DS and dup-APP that may yield further pathophysiological insight.

scholarly journals Ten Reasons Why People With Down Syndrome are Protected From the Development of Most Solid Tumors -A Review

2021 ◽  
Vol 12 ◽  
Author(s):  
Marta Pilar Osuna-Marco ◽  
Mónica López-Barahona ◽  
Blanca López-Ibor ◽  
Águeda Mercedes Tejera
Keyword(s):  
Down Syndrome ◽  
Solid Tumors ◽  
Tumor Suppressor Genes ◽  
Wilms Tumor ◽  
Extra Chromosome ◽  
Germ Cell Tumors ◽  
Chromosome 21 ◽  
Testicular Tumors ◽  
Unique Pattern ◽  
Increased Risk

People with Down syndrome have unique characteristics as a result of the presence of an extra chromosome 21. Regarding cancer, they present a unique pattern of tumors, which has not been fully explained to date. Globally, people with Down syndrome have a similar lifetime risk of developing cancer compared to the general population. However, they have a very increased risk of developing certain tumors (e.g., acute leukemia, germ cell tumors, testicular tumors and retinoblastoma) and, on the contrary, there are some other tumors which appear only exceptionally in this syndrome (e.g., breast cancer, prostate cancer, medulloblastoma, neuroblastoma and Wilms tumor). Various hypotheses have been developed to explain this situation. The genetic imbalance secondary to the presence of an extra chromosome 21 has molecular consequences at several levels, not only in chromosome 21 but also throughout the genome. In this review, we discuss the different proposed mechanisms that protect individuals with trisomy 21 from developing solid tumors: genetic dosage effect, tumor suppressor genes overexpression, disturbed metabolism, impaired neurogenesis and angiogenesis, increased apoptosis, immune system dysregulation, epigenetic aberrations and the effect of different microRNAs, among others. More research into the molecular pathways involved in this unique pattern of malignancies is still needed.

scholarly journals Noninvasive Prenatal Testing by Nanopore Sequencing of Maternal Plasma DNA: Feasibility Assessment

2015 ◽  
Vol 61 (10) ◽  
pp. 1305-1306 ◽  
Author(s):  
Suk Hang Cheng ◽  
Peiyong Jiang ◽  
Kun Sun ◽  
Yvonne K Y Cheng ◽  
K C Allen Chan ◽  
...  
Keyword(s):  
Prenatal Testing ◽  
Maternal Plasma ◽  
Nanopore Sequencing ◽  
Plasma Dna ◽  
Noninvasive Prenatal Testing ◽  
Feasibility Assessment

scholarly journals Universal Haplotype-Based Noninvasive Prenatal Testing for Single Gene Diseases

2017 ◽  
Vol 63 (2) ◽  
pp. 513-524 ◽  
Author(s):  
Winnie W I Hui ◽  
Peiyong Jiang ◽  
Yu K Tong ◽  
Wing-Shan Lee ◽  
Yvonne K Y Cheng ◽  
...  
Keyword(s):  
Single Gene ◽  
Family Members ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Nucleotide Polymorphisms ◽  
Plasma Dna ◽  
Sequencing Technology ◽  
Noninvasive Prenatal Testing ◽  
Haplotype Phasing ◽  
Mutational Status

Abstract BACKGROUND Researchers have developed approaches for the noninvasive prenatal testing of single gene diseases. One approach that allows for the noninvasive assessment of both maternally and paternally inherited mutations involves the analysis of single nucleotide polymorphisms (SNPs) in maternal plasma DNA with reference to parental haplotype information. In the past, parental haplotypes were resolved by complex experimental methods or inferential approaches, such as through the analysis of DNA from other affected family members. Recently, microfluidics-based linked-read sequencing technology has become available and allows the direct haplotype phasing of the whole genome rapidly. We explored the feasibility of applying this direct haplotyping technology in noninvasive prenatal testing. METHODS We first resolved the haplotypes of parental genomes with the use of linked-read sequencing technology. Then, we identified SNPs within and flanking the genes of interest in maternal plasma DNA by targeted sequencing. Finally, we applied relative haplotype dosage analysis to deduce the mutation inheritance status of the fetus. RESULTS Haplotype phasing and relative haplotype dosage analysis of 12 out of 13 families were successfully achieved. The mutational status of these 12 fetuses was correctly classified. CONCLUSIONS High-throughput linked-read sequencing followed by maternal plasma-based relative haplotype dosage analysis represents a streamlined approach for noninvasive prenatal testing of inherited single gene diseases. The approach bypasses the need for mutation-specific assays and is not dependent on the availability of DNA from other affected family members. Thus, the approach is universally applicable to pregnancies at risk for the inheritance of a single gene disease.

Noninvasive Prenatal Testing Using Cell‐Free Fetal DNA in Maternal Plasma

2015 ◽  
Vol 84 (1) ◽  
Author(s):  
Nilesh Dharajiya ◽  
Tricia Zwiefelhofer ◽  
Xiaojun Guan ◽  
Vach Angkachatchai ◽  
Juan‐Sebastian Saldivar
Keyword(s):  
Prenatal Testing ◽  
Maternal Plasma ◽  
Noninvasive Prenatal Testing ◽  
Fetal Dna ◽  
Cell Free Fetal Dna

scholarly journals Noninvasive prenatal testing for chromosome aneuploidies and subchromosomal microdeletions/microduplications in a cohort of 42,910 single pregnancies with different clinical features

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Yibo Chen ◽  
Qi Yu ◽  
Xiongying Mao ◽  
Wei Lei ◽  
Miaonan He ◽  
...  
Keyword(s):  
Clinical Features ◽  
Sex Chromosome ◽  
Prenatal Testing ◽  
Maternal Plasma ◽  
Trisomy 13 ◽  
Noninvasive Prenatal Testing ◽  
Detection Rates ◽  
Non Invasive ◽  
Cell Free Fetal Dna ◽  
Sex Chromosome Aneuploidies

Abstract Background Since the discovery of cell-free DNA (cfDNA) in maternal plasma, it has opened up new approaches for non-invasive prenatal testing. With the development of whole-genome sequencing, small subchromosomal deletions and duplications could be found by NIPT. This study is to review the efficacy of NIPT as a screening test for aneuploidies and CNVs in 42,910 single pregnancies. Methods A total of 42,910 single pregnancies with different clinical features were recruited. The cell-free fetal DNA was directly sequenced. Each of the chromosome aneuploidies and the subchromosomal microdeletions/microduplications of PPV were analyzed. Results A total of 534 pregnancies (1.24%) were abnormal results detected by NIPT, and 403 pregnancies had underwent prenatal diagnosis. The positive predictive value (PPV) for trisomy 21(T21), trisomy 18 (T18), trisomy 13 (T13), sex chromosome aneuploidies (SCAs), and other chromosome aneuploidy was 79.23%, 54.84%, 13.79%, 33.04%, and 9.38% respectively. The PPV for CNVs was 28.99%. The PPV for CNVs ≤ 5 Mb is 20.83%, for within 5–10 Mb 50.00%, for > 10 Mb 27.27% respectively. PPVs of NIPT according to pregnancies characteristics are also different. Conclusion Our data have potential significance in demonstrating the usefulness of NIPT profiling not only for common whole chromosome aneuploidies but also for CNVs. However, this newest method is still in its infancy for CNVs. There is still a need for clinical validation studies with accurate detection rates and false positive rates in clinical practice.

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