A Challenging Prenatal QF-PCR Rapid Aneuploidy Test Result Caused by a Maternally Inherited Triplication within Chromosome Xq26.2

2018 ◽  
Vol 156 (1) ◽  
pp. 5-8
Author(s):  
Amy Inkster ◽  
Mary Ann Thomas ◽  
Nadine S. Gamache ◽  
Michael Chan ◽  
Pernilla Stenroos ◽  
...  
Keyword(s):  
Microsatellite Marker ◽  
X Chromosome ◽  
Copy Number ◽  
Sex Chromosome ◽  
Chromosome Analysis ◽  
First Trimester ◽  
Chromosomal Microarray ◽  
Normal Male ◽  
Fluorescent Polymerase Chain Reaction ◽  
Male Karyotype

The aim of this study was to investigate the origin of the biallelic trisomic amplification pattern of the X chromosome microsatellite marker DXS1187 in an otherwise normal male fetus, identified on routine rapid aneuploidy detection (RAD) testing by quantitative fluorescent-polymerase chain reaction (QF-PCR). Amniocentesis was performed on a 35-year-old female at 15 weeks, 2 days gestation for a positive first trimester screen. QF-PCR, metaphase FISH, and chromosomal microarray were carried out on both maternal and fetal DNA. Fetal QF-PCR showed a biallelic trisomic pattern for the X chromosome microsatellite marker DXS1187, with an otherwise normal male amplification pattern at all other sex chromosome markers. Chromosome analysis performed on cultured amniocytes showed a normal male karyotype. Chromosome microarray analysis identified a maternally inherited 304-kb copy number triplication within chromosome Xq26.2 encompassing the DXS1187 marker. The maternally inherited X chromosome harbors an apparently tandem 304-kb triplication that overlaps the DXS1187 marker. As the triplicated region is devoid of clinically relevant genes, it was considered as likely benign in the fetus. Postnatal follow-up reported a healthy male newborn. To our knowledge, this is a unique case demonstrating a “benign” copy number imbalance involving the DXS1187 marker detected by prenatal QF-PCR RAD.

scholarly journals Identification of sex chromosomes using genomic and cytogenetic methods in a range-expanding spider, Argiope bruennichi (Araneae: Araneidae)

2021 ◽  
Author(s):  
Monica M Sheffer ◽  
Mathilde M Cordellier ◽  
Martin Forman ◽  
Malte Grewoldt ◽  
Katharina Hoffmann ◽  
...  
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Gc Content ◽  
Sexually Dimorphic ◽  
Behavioral Experiments ◽  
X Chromosomes ◽  
Male Karyotype ◽  
And Behavior

Differences between sexes in growth, ecology and behavior strongly shape species biology. In some animal groups, such as spiders, it is difficult or impossible to identify the sex of juveniles. This information would be useful for field surveys, behavioral experiments, and ecological studies on e.g. sex ratios and dispersal. In species with sex chromosomes, sex can be determined based on the specific sex chromosome complement. Additionally, information on the sequence of sex chromosomes provides the basis for studying sex chromosome evolution. We combined cytogenetic and genomic data to identify the sex chromosomes in the sexually dimorphic spider Argiope bruennichi, and designed RT-qPCR sex markers. We found that genome size and GC content of this spider falls into the range reported for the majority of araneids. The male karyotype is formed by 24 acrocentric chromosomes with an X1X20 sex chromosome system, with little similarity between X chromosomes, suggesting origin of these chromosomes by X chromosome fission or early duplication of an X chromosome and subsequent independent differentiation of the copies. Our data suggest similarly sized X chromosomes in A. bruennichi. They are smaller chromosomes of the complement. Our findings open the door to new directions in spider evolutionary and ecological research.

scholarly journals THE EFFECT OF X-CHROMOSOME COPY NUMBER ON BLASTULATION TIME IN EMBRYOS WITH SEX CHROMOSOME ANEUPLOIDIES

2021 ◽  
Vol 116 (3) ◽  
pp. e149-e150
Author(s):  
Ann Korkidakis ◽  
Abigail Groff ◽  
Jaimin S. Shah ◽  
Angela Q. Leung ◽  
Alan S. Penzias ◽  
...  
Keyword(s):  
X Chromosome ◽  
Copy Number ◽  
Sex Chromosome ◽  
Chromosome Copy Number ◽  
Sex Chromosome Aneuploidies

Health Supervision for Children With Turner Syndrome

PEDIATRICS ◽  
1995 ◽  
Vol 96 (6) ◽  
pp. 1166-1173
Author(s):  
Keyword(s):  
Short Stature ◽  
Turner Syndrome ◽  
X Chromosome ◽  
Sex Chromosome ◽  
First Trimester ◽  
Clinical Findings ◽  
Chromosome Constitution ◽  
Birth Prevalence ◽  
Frequent Use ◽  
Wide Range

This set of guidelines is designed to assist the pediatrician in caring for the child in whom the diagnosis of Turner syndrome has been confirmed by karyotype. Although the pediatrician's first contact with the child is usually during infancy, occasionally the pregnant woman who has been given the prenatal diagnosis of Turner syndrome will be referred for advice. Therefore, these guidelines offer advice for this situation as well. Turner syndrome, as used here, refers to a condition in which there is short stature and ovarian dysgenesis in females because of the absence of a normal second sex chromosome. Nonchrornosomal gonadal dysgenesis is excluded. The birth prevalence of Turner syndrome has been estimated to be from 1:2000 to 1:5000 female live births. About 1% to 2% of all conceptuses have a 45,X chromosome constitution. Of these, the majority (99%) spontaneously abort, usually during the first trimester of pregnancy. With the more frequent use of ultrasound, it is recognized that some pregnancies with a fetal 45,X chromosome constitution progressing into the second trimester are associated with nuchal cysts, severe lymphedema, or hydrops fetalis. These pregnancies are associated with a high frequency of fetal death. PHENOTYPE Pediatricians are most familiar with the clinical findings that prompt the diagnosis in children, namely, short stature and the classic Turner syndrome features such as lymphederna, webbed neck, low posterior hair line, and cubitus valgus. A wide range of clinical abnormalities may be found (Table 1). Turner syndrome, however, is not always accompanied by distinctive features and most often is not diagnosed in infancy.

scholarly journals Parental Origin and Cell Stage Errors in X-Chromosome Polysomy 49, XXXXY

2009 ◽  
Vol 12 (1) ◽  
pp. 45-50
Author(s):  
A Guzel ◽  
O Demirhan ◽  
A Pazarbasi ◽  
B Yuksel
Keyword(s):  
X Chromosome ◽  
Language Impairment ◽  
Sex Chromosome ◽  
Peripheral Blood Cell ◽  
Banding Technique ◽  
Parental Origin ◽  
Speech Impairment ◽  
Cell Stage ◽  
Skeletal Defects ◽  
Fluorescent Polymerase Chain Reaction

Parental Origin and Cell Stage Errors in X-Chromosome Polysomy 49, XXXXYPolysomy 49, XXXXY is a rare sex chromosome aneuploidy syndrome characterized by mental retardation, severe speech impairment, craniofacial abnormalities, multiple skeletal defects and genital abnormalities. We describe a patient with 49, XXXXY syndrome who had many characteristics of Fraccaro syndrome; language impairment, mongoloid slant, epicanthal folds, cryptorchidism, umbilical hernia and dysmyelinization in his brain. A GTG-banding technique was used for karyotype analysis of peripheral blood cell cultures. The parental origin of polysomy X was identified by using quantitative fluorescent polymerase chain reaction (QF-PCR) with seven short tandem repeat (STR) markers specific for the X/Y-chromosome which revealed that all the X-chromosomes were of maternal origin. This report provides evidence for successive non disjunctions in maternal meiosis I and II.

scholarly journals Maternal Parvovirus B19 Infection Causing First-Trimester Increased Nuchal Translucency and Fetal Hydrops

2019 ◽  
Vol 2019 ◽  
pp. 1-4 ◽  
Author(s):  
Olivia Grubman ◽  
Farrah Naz Hussain ◽  
Zoe Nelson ◽  
Lois Brustman
Keyword(s):  
Parvovirus B19 ◽  
Peak Systolic Velocity ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Normal Male ◽  
Fetal Hydrops ◽  
Erythroid Progenitor ◽  
Parvovirus B19 Infection ◽  
Male Karyotype ◽  
Increased Nuchal Translucency

This is a case report of a 31-year-old primigravida who was diagnosed with an asymptomatic acute parvovirus B19 infection in the second trimester of pregnancy and its suspected association with an increased nuchal translucency (NT) measurement. Parvovirus B19 is a single-stranded DNA virus that is cytotoxic to erythroid progenitor cells, causing inhibition of erythropoiesis. While maternal disease is usually mild, fetal infection can result in spontaneous abortion, aplastic anemia, nonimmune fetal hydrops, and fetal demise. This fetus had an increased NT of 3.2 mm at 11 weeks’ gestation with a normal male karyotype and microarray analysis on chorionic villi sampling, in addition to a normal fetal echocardiogram at 15 weeks’ gestation. The anatomy scan at 20 weeks’ and 1-day gestation revealed fetal ascites, pleural effusion, and increased middle cerebral artery peak systolic velocity suspicious for fetal anemia. At this time, maternal serology for parvovirus was positive for IgM and IgG. Amniocentesis, cordocentesis, and intrauterine transfusion were performed. The amniocentesis revealed elevated parvovirus B19 DNA, quantitative PCR (2,589,801 copies/mL, reference range <100 copies/mL). The patient delivered a viable male fetus at 37 weeks’ and 6-day gestation, without sequelae of the previously noted hydrops. Parvovirus B19 infection should be a consideration when evaluating increased NT and hydrops fetalis. It warrants close antepartum surveillance and possible intrauterine fetal transfusions. With prompt recognition, proper treatment, and surveillance, these patients can go on to achieve healthy term deliveries. Long-term outcomes of delivered infants require further study.

scholarly journals Copy Number Variations Are More Frequent on Chromosome 14 as Compared to X Chromosome in Suspected Turner Syndrome Girls - A Chromosomal Microarray Analysis

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A796-A797
Author(s):  
Naincy Purwar ◽  
Pradeep Tiwari ◽  
Aditya Saxena ◽  
Nitish Mathur ◽  
Himanshu Sharma ◽  
...  
Keyword(s):  
Turner Syndrome ◽  
X Chromosome ◽  
Copy Number ◽  
False Negative ◽  
Enrichment Analysis ◽  
Copy Number Variations ◽  
Chromosomal Microarray ◽  
Study Cohort ◽  
Chromosomal Microarray Analysis ◽  
Chromosome 14

Abstract Introduction: Turner syndrome(TS) is defined by complete/partial monosomy of X chromosome in association with classic clinical manifestations. Conventional karyotyping is the gold standard test for diagnosis of TS. However it is labour intensive and inaccurate for detecting mosaicism, marker chromosomes and sub-microscopic deletions/duplications. TS is characterized by heterogeneous phenotypes despite identical karyotypes and precise genotype-phenotype correlations have not yet been deciphered. Presence of TS specific features in absence of X chromosome abnormality, evokes the hypothesis of possible autosomal involvement. Here, we report detailed Chromosomal microarray (CMA) analysis of 47 girls with clinically suspected TS, using Affymetrix CytoScan 750K array. Materials and Methods: The clinical diagnosis of TS was based on recommendations by clinical practice guidelines from 2016 Cincinnati International TS meeting. Peripheral venous sample was collected in EDTA tubes and DNA was extracted using Qiagen-DNAeasy Blood and Tissue kit (Cat No. 69504). DNA samples were then hybridized to the Affymetrix CytoScan 750K array as per manufacturer’s instructions. The data obtained was analysed using Chromosomal Analysis suite software and public genomic databases- ISCA, OMIM, DGV, DECIPHER. For bioinformatic analysis, all the genes (172) implicated in TS were retrieved from DisGeNET database. A TS-interactome of 4033 genes was then constructed from these genes and their first-degree neighbours from complete human interactome. Thereafter compilation was done based on CMA results and a protein-protein interaction network of 316 nodes was constructed. Results: Mean age of study cohort was 15.8 ± 3.64 years with short stature being the most common presenting phenotype (91.4%). CMA analysis detected copy number variations (CNVs) on chromosome 14 in 42 (89.3%) of 47 cases while X chromosome CNVs were present in only 28 (59.5%) cases, with all patients clinically qualifying as TS. Total 445 CNVs were discovered on X chromosome and 64 CNVs were found on Chromosome 14 exhibiting either CNV gain at 14q32.33 or CNV loss at 14q11.2 or both. The 30 cell karyotype was available for 27 patients and was found to be false negative in 7 (14.8%) patients. Also, 6 out of 47 cases had Y chromosome translocation detected on CMA that failed detection by karyotype. On enrichment analysis, thirty KEGG pathways were found to be enriched by the overlapping genes between TS-interactome and the interactome constructed by genes located within 14q11.2, and 14q32.33 67% of genes (212) in this network overlap with TS-interactome. Conclusions: CMA is a superior diagnostic modality for TS than karyotyping. Functional interactomes between Chromosome X and Chromosome 14 on enrichment analysis reveal novel pathways underlying phenotypic manifestations.

scholarly journals Optical genome mapping as a next-generation cytogenomic tool for detection of structural and copy number variations for prenatal genomic analyses

2021 ◽  
Author(s):  
Nikhil Shri Sahajpal ◽  
Hayk Barseghyan ◽  
Ravindra Kolhe ◽  
Alex Hastie ◽  
Alka Chaubey
Keyword(s):  
Copy Number ◽  
Southern Blotting ◽  
Sex Chromosome ◽  
Genome Mapping ◽  
Genetic Disorders ◽  
Standard Of Care ◽  
Copy Number Variations ◽  
Repeat Expansion ◽  
Chromosomal Microarray ◽  
Next Generation

Global medical associations (ACOG, ISUOG, ACMG) recommend diagnostic prenatal testing for the detection and prevention of genetic disorders. Historically, cytogenetic methods such as karyotype analysis, fluorescent in situ hybridization (FISH), and chromosomal microarray (CMA) are utilized worldwide to diagnose common syndromes. However, the limitations of each of these methods, either performed in tandem or simultaneously, demonstrates the need of a revolutionary technology that can alleviate the need of multiple technologies. Optical genome mapping (OGM) is a novel technology that fills this void by being able to detect all classes of structural variations (SVs), including copy number variations (CNVs). OGM is being adopted by laboratories as a next-generation cytogenomic tool for both postnatal constitutional genetic disorders and hematological malignancies. This commentary highlights the potential of OGM to become a standard of care in prenatal genetic testing by its ability to identify large balanced and unbalanced SVs (currently the strength of karyotyping and metaphase FISH), CNVs (by CMA), repeat contraction disorders (by Southern blotting) and multiple repeat expansion disorders (by PCR based methods or Southern blotting). Also, next-generation sequencing (NGS) methods are excellent at detecting sequencing variants but are unable to accurately detect the repeat regions of the genome which limits the ability to detect all classes of SVs. Notably, multiple molecular methods are used to identify repeat expansion and contraction disorders in routine clinical laboratories around the world. With non-invasive prenatal screening test (NIPT) as the standard of care screening assay for all global pregnancies, we anticipate OGM as a high-resolution cytogenomic diagnostic tool employed following a positive NIPT screen or for high-risk pregnancies with an abnormal ultrasound. Accurate detection of all types of genetic disorders by OGM, such as liveborn aneuploidies, sex chromosome anomalies, microdeletion/microduplication syndromes, repeat expansion/contra5ction disorders is key to reducing the global burden of genetic disorders.

INTRASPECIES AUTOSOMAL POLYMORPHISM AND CHROMOSOME REPLICATION IN AKODON MOLINAE (RODENTIA: CRICETIDAE)

1969 ◽  
Vol 11 (2) ◽  
pp. 233-242 ◽  
Author(s):  
N. O. Bianchi ◽  
J. Contreras ◽  
F. N. Dulout
Keyword(s):  
Bone Marrow ◽  
Y Chromosome ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Chromosome Analysis ◽  
Chromosome Replication ◽  
Chromosome 1 ◽  
Submetacentric Chromosome ◽  
Sex Chromatin ◽  
S Period

Cell spreads from bone marrow, spleen, testis and liver of four male and four female Akodon molinae (Rodentia:Cricetidae) were used for chromosome analysis and sex chromatin scoring. Chromosome replication at the beginning and end of the S period were analysed in bone marrow cells.In five animals (three males and two females) the diploid chromosome number was 42; the other three (1 male and 2 females) had a modal number of 43. In the former animals pairs 1,2,19,20 and the Y chromosome were easily identified morphologically. Chromosomes 1 were large and metacentric. In specimens with 43 chromosomes, pairs 2-20-XY were similar to those of animals with 42. Instead of having two number 1 homologues, these animals showed three unpaired chromosomes, one chromosome 1, one subterminal chromosome (1a) homologue of the long arm of the chromosome 1 and one submetacentric chromosome (1b) homologue of the short arm of the chromosome 1 Chromosomes 1a and 1b were considered to have arisen by a Robertsonian mechanism of centric fission of chromosome 1 plus a pericentric inversion.Studies of sex chromosome replication showed that the Y chromosome was the last to start and to end DNA synthesis in male complements. In females one X chromosome was the last to start replication. No late replicating X chromosome at the end of the S period was found. Coincidently, no sex chromatin could be detected in females.Analysis of late replication patterns in chromosomes 1, 1a and 1b, indicates that pericentric inversions can shift the replicating moment of the chromosomal regions involved in the rearrangement.

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