scholarly journals Multicolor-FISH Characterization of a Prenatal Mosaicism for a Chromosomal Rearrangement Undetected by Molecular Cytogenetics

2021 ◽  
pp. 1-10
Author(s):  
Laura Mary ◽  
Philippe Loget ◽  
Sylvie Odent ◽  
Dominique Aussel ◽  
Gwenaelle Le Bouar ◽  
...  
Keyword(s):  
Chromosomal Rearrangement ◽  
Chromosomal Rearrangements ◽  
Molecular Cytogenetics ◽  
Molecular Techniques ◽  
Chromosome 17 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Multicolor Fish ◽  
Partial Monosomy ◽  
Additional Material

Fetal mosaicism for chromosomal rearrangements remains a challenge to diagnose, even in the era of whole-genome sequencing. We present here a case of fetal mosaicism for a chromosomal rearrangement explored in amniocytes and fetal muscle, consisting of a major cell population (95%) with partial monosomy 4q and a minor population (5%) with additional material replacing the 4qter deleted segment. Molecular techniques (MLPA, array-CGH) failed to assess the origin of this material. Only multicolor-FISH identified the additional segment on chromosome 4 as derived from chromosome 17. Due to the poor prognosis, the couple chose to terminate the pregnancy. Because of low-level mosaicism, chromosomal microarray analysis (CMA), now considered as first-tier prenatal genetic analysis, did not allow the identification of the minor cell line. In case of large CNVs (>5 Mb) detected by CMA, karyotyping may be considered to elucidate the mechanism of the underlying rearrangement and eliminate mosaicism.

scholarly journals De novo mosaic and partial monosomy of chromosome 21 in a case with superior vena cava duplication

2020 ◽  
Author(s):  
Abul Kalam Azad ◽  
Lindsay Yanakakis ◽  
Samantha Issleb ◽  
Jessica Turina ◽  
Kelli Drabik ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
De Novo ◽  
Superior Vena ◽  
Vena Cava ◽  
Chromosome 21 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Partial Monosomy ◽  
Increased Risk

Abstract Background Full or partial monosomy of chromosome (chr) 21 is a very rare abnormal cytogenetic finding. It is characterized by variable sizes and deletion breakpoints on the long arm (q) of chr 21 that lead to a broad spectrum of phenotypes that include an increased risk of birth defects, developmental delay and intellectual deficit. Case presentation: We report a 37-year-old G1P0 woman initially screened by non-invasive prenatal testing with no positive findings that was followed by an 18-week anatomy scan with a fetal finding of duplication of the superior vena cava (SVC). The medical and family history was otherwise uneventful. After appropriate genetic counseling, amniocentesis was performed to evaluate suspected chromosomal anomalies. Conclusions Fluorescent in situ hybridization revealed loss of one chr 21 signal that was further delineated by chromosomal microarray analysis on uncultured amniocytes as a terminal 10 Mb deletion on chr 21q. Karyotype and microarrays on cultured amniocytes showed two cell lines for a mosaic 21q terminal deletion and monosomy 21. The combined molecular cytogenetics results reported as mos 45,XX,-21[10]/46,XX,del(21)(q22)dn[20].nuc ish(D21S342/D21S341/D21S259 × 1)[100].arr[GRCh37] 21q11.2q22.12(15412676_36272993)x1 ~ 2,21q22.12q22.3(36431283_47612400)x1. Parental chromosomal analysis revealed normal karyotypes. Thus, this was a de novo mosaic full and partial monosomy of chr 21 in a case with SVC duplication. Despite the association of congenital heart disease with monsomy 21 we could not find any published literature or online databases for this cytogenetic abnormality. The patient terminated the pregnancy following the abnormal molecular cytogenetic results due to the possible challenges the baby would face if carried to term.

scholarly journals Genetic counseling for a prenatal diagnosis of structural chromosomal abnormality with high-resolution analysis using a single nucleotide polymorphism microarray

2016 ◽  
Vol 6 (3) ◽  
Author(s):  
Akiko Takashima ◽  
Naoki Takeshita ◽  
Toshihiko Kinoshita
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Genetic Counseling ◽  
Chromosomal Abnormality ◽  
Chromosomal Rearrangements ◽  
Genetic Diagnosis ◽  
Chromosomal Microarray ◽  
Normal Male ◽  
Chromosomal Microarray Analysis ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide

A 41-year old pregnant woman underwent amniocentesis to conduct a conventional karyotyping analysis; the analysis reported an abnormal karyotype: 46,XY,add(9)(p24). Chromosomal microarray analysis (CMA) is utilized in prenatal diagnoses. A single nucleotide polymorphism microarray revealed a male fetus with balanced chromosomal translocations on 9p and balanced chromosomal rearrangements, but another chromosomal abnormality was detected. The fetus had microduplication. The child was born as a phenotypically normal male. CMA is a simple and informative procedure for prenatal genetic diagnosis. CMA is the detection of chromosomal variants of unknown clinical significance; therefore, genetic counseling is important during prenatal genetic testing.

scholarly journals Chromosomal Microarray Analysis versus Karyotyping in Fetuses with Increased Nuchal Translucency

2019 ◽  
Vol 7 (3) ◽  
pp. 40 ◽  
Author(s):  
Rita Cicatiello ◽  
Piero Pignataro ◽  
Antonella Izzo ◽  
Nunzia Mollo ◽  
Lucia Pezone ◽  
...  
Keyword(s):  
Microarray Analysis ◽  
Chromosomal Rearrangements ◽  
Prenatal Testing ◽  
Normal Karyotype ◽  
Nuchal Translucency ◽  
Cystic Hygroma ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Increased Nuchal Translucency

We have carried out a retrospective study of chromosome anomalies associated with increased nuchal translucency (NT) in order to compare yield rates of karyotype, chromosome microarray analysis (CMA), and non-invasive prenatal testing (NIPT) in this condition. Presenting with increased NT or cystic hygroma ≥3.5 mm as an isolated sign, 249 fetuses underwent karyotype and/or CMA from 11 to 18 gestational weeks. Karyotype and fluorescence in situ hybridization (FISH) analyses detected 103 chromosomal anomalies including 95 aneuploidies and eight chromosomal rearrangements or derivatives. Further, seven pathogenic copy number variants (CNV), five likely pathogenic CNVs, and 15 variants of unknown significance (VOUS) were detected by CMA in fetuses with normal karyotype. Genetic testing is now facing new challenges due to results with uncertain clinical impacts. Additional investigations will be necessary to interpret these findings. More than 15% of the anomalies that we have diagnosed with invasive techniques could not be detected by NIPT. It is therefore definitely not recommended in the case of ultrasound anomalies. These results, while corroborating the use of CMA in fetuses with increased NT as a second tier after rapid aneuploidy testing, do not suggest a dismissal of karyotype analysis.

Angelman Syndrome Caused by Chromosomal Rearrangements: A Case Report of 46,XX,+der(13)t(13;15)(q14.1;q12)mat,-15 with an Atypical Phenotype and Review of the Literature

2016 ◽  
Vol 149 (4) ◽  
pp. 247-257
Author(s):  
Yo Niida ◽  
Hitoshi Sato ◽  
Mamoru Ozaki ◽  
Masatsune Itoh ◽  
Kanju Ikeno ◽  
...  
Keyword(s):  
Angelman Syndrome ◽  
De Novo ◽  
Chromosomal Rearrangements ◽  
Snp Array ◽  
Uniparental Disomy ◽  
Parental Origin ◽  
Review Of The Literature ◽  
Balanced Translocation ◽  
Multicolor Fish ◽  
Partial Monosomy

Less than 1% of the cases with Angelman syndrome (AS) are caused by chromosomal rearrangements. This category of AS is not well defined and may manifest atypical phenotypes. Here, we report a girl with AS due to der(13)t(13;15)(q14.1;q12)mat. SNP array detected the precise deletion/duplication points and the parental origin of the 15q deletion. Multicolor FISH confirmed a balanced translocation t(13;15)(q14.1;q12) in her mother. Her facial appearance showed some features of dup(13)(pter→q14). Also, she lacked the most characteristic and unique behavioral symptoms of AS, i.e., frequent laughter, happy demeanor, and easy excitability. A review of the literature indicated that AS cases caused by chromosomal rearrangements can be classified into 2 major categories and 4 groups. The first category is paternal uniparental disomy 15, which is subdivided into isodisomy by de novo rob(15;15) and heterodisomy caused by paternal translocation. The second category is the deletion of the AS locus due to maternal reciprocal translocation, which is subdivided into 2 groups associated with partial monosomy by 3:1 segregation and partial trisomy by adjacent-2 segregation. Classification into these categories facilitates the understanding of the mechanisms of chromosomal rearrangements and helps in accurate diagnosis and genetic counseling of these rare forms of AS.

scholarly journals Prenatal Diagnosis and Molecular Cytogenetic Characterization of Copy Number Variations on 4p15.2p16.3, Xp22.31, and 12p11.1q11 in a Fetus with Ultrasound Anomalies: A Case Report and Literature Review

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Han Zhang ◽  
Qi Xi ◽  
Xiangyin Liu ◽  
Fagui Yue ◽  
Hongguo Zhang ◽  
...  
Keyword(s):  
Copy Number ◽  
De Novo ◽  
Genetic Disorders ◽  
Chromosomal Rearrangements ◽  
Copy Number Variations ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosome 2 ◽  
Cytogenetic Characterization

Chromosomal rearrangements, such as duplications/deletions, can lead to a variety of genetic disorders. Herein, we reported a prenatal case with right aortic arch and aberrant left subclavian artery, consisting of a complex chromosomal copy number variations. Routine cytogenetic analysis described the chromosomal karyotype as 46,XY, add (2)(q37) for the fetus. However, the chromosomal microarray analysis (CMA) identified a 22.4 Mb duplication in chromosome 4p16.3p15.2, a 3.96 Mb microduplication in 12p11.1q11, and a 1.68 Mb microdeletion in Xp22.31. Fluorescence in situ hybridization (FISH) using a chromosome 4 painting probe was found to hybridize to the terminal of chromosome 2q on the fetus, thus confirming that the extra genetic materials of chromosome 2 was actually trisomy 4p detected through CMA. Meanwhile, the parental karyotypes were normal, which proved that the add (2) was de novo for fetus. The duplication of Wolf-Hirschhorn syndrome critical region (WHSCR) and X-linked recessive ichthyosis associated with Xp22.31 deletion separately were considered potentially pathogenic causes although other abnormalities involving these syndromes were not observed. For prenatal cases, the combined utilization of ultrasonography, traditional cytogenetic, and molecular diagnosis technology will enhance better diagnostic benefits, offer more detailed genetic counselling, and assess the prognosis of the fetuses.

scholarly journals De novo mosaic and partial monosomy of chromosome 21 in a case with superior vena cava duplication

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Abul Kalam Azad ◽  
Lindsay Yanakakis ◽  
Samantha Issleb ◽  
Jessica Turina ◽  
Kelli Drabik ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
De Novo ◽  
Superior Vena ◽  
Vena Cava ◽  
Chromosome 21 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Partial Monosomy ◽  
Increased Risk

Abstract Background Full or partial monosomy of chromosome (chr) 21 is a very rare abnormal cytogenetic finding. It is characterized by variable sizes and deletion breakpoints on the long arm (q) of chr 21 that lead to a broad spectrum of phenotypes that include an increased risk of birth defects, developmental delay and intellectual deficit. Case presentation We report a 37-year-old G1P0 woman initially screened by non-invasive prenatal testing with no positive findings that was followed by an 18-week anatomy scan with a fetal finding of duplication of the superior vena cava (SVC). The medical and family history was otherwise uneventful. After appropriate genetic counseling, amniocentesis was performed to evaluate suspected chromosomal anomalies. Conclusions Interphase fluorescent in situ hybridization revealed loss of one chr 21 signal that was further delineated by chromosomal microarray analysis on uncultured amniocytes as a terminal 10 Mb deletion on chr 21q. Karyotype and microarrays on cultured amniocytes showed two cell lines for a mosaic 21q terminal deletion and monosomy 21. The combined molecular cytogenetics results reported following the ISCN 2016 guideline as mos 46,XX,del(21)(q22)dn[20]/45,XX,-21dn[10].nuc ish(D21S342/D21S341/D21S259x1)[100].arr[GRCh37] 21q11.2q22.12(15412676_36272993)x1~2,21q22.12q22.3(36431283_47612400)x1. Parental chromosomal analysis revealed normal karyotypes. Thus, this was a de novo mosaic full and partial monosomy of chr 21 in a case with SVC duplication. Despite the association of congenital heart disease with monsomy 21 we could not find any published literature or online databases for this cytogenetic abnormality. The patient terminated the pregnancy following the abnormal molecular cytogenetic results due to the possible challenges the baby would face if carried to term.

scholarly journals De novo mosaic and partial monosomy of chromosome 21 in a case with superior vena cava duplication

2020 ◽  
Author(s):  
Abul Kalam Azad ◽  
Lindsay Yanakakis ◽  
Samantha Issleb ◽  
Jessica Turina ◽  
Kelli Drabik ◽  
...  
Keyword(s):  
Superior Vena Cava ◽  
De Novo ◽  
Superior Vena ◽  
Vena Cava ◽  
Chromosome 21 ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Chromosomal Anomalies ◽  
Partial Monosomy ◽  
Increased Risk

Abstract Background: Full or partial monosomy of chromosome (chr) 21 is a very rare abnormal cytogenetic finding. It is characterized by variable sizes and deletion breakpoints on the long arm (q) of chr 21 that lead to a broad spectrum of phenotypes that include an increased risk of birth defects, developmental delay and intellectual deficit.Case presentation: We report a 37-year-old G1P0 woman initially screened by non-invasive prenatal testing with no positive findings that was followed by an 18-week anatomy scan with a fetal finding of duplication of the superior vena cava (SVC). The medical and family history was otherwise uneventful. After appropriate genetic counseling, amniocentesis was performed to evaluate suspected chromosomal anomalies.Conclusions: Interphase fluorescent in situ hybridization revealed loss of one chr 21 signal that was further delineated by chromosomal microarray analysis on uncultured amniocytes as a terminal 10 Mb deletion on chr 21q. Karyotype and microarrays on cultured amniocytes showed two cell lines for a mosaic 21q terminal deletion and monosomy 21. The combined molecular cytogenetics results reported following the ISCN 2016 guideline as mos 46,XX,del(21)(q22)dn[20]/45,XX,-21dn[10].nuc ish(D21S342/D21S341/D21S259x1)[100].arr[GRCh37] 21q11.2q22.12(15412676_36272993)x1~2,21q22.12q22.3(36431283_47612400)x1. Parental chromosomal analysis revealed normal karyotypes. Thus, this was a de novo mosaic full and partial monosomy of chr 21 in a case with SVC duplication. Despite the association of congenital heart disease with monsomy 21 we could not find any published literature or online databases for this cytogenetic abnormality. The patient terminated the pregnancy following the abnormal molecular cytogenetic results due to the possible challenges the baby would face if carried to term.

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