scholarly journals Mosaic duplication of 8q24.1q24.3 detected by chromosomal microarray but not karyotyping in two unrelated fetuses with cardiac defects

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shaobin Lin ◽  
Shufang Huang ◽  
Xueling Ou ◽  
Heng Gu ◽  
Yonghua Wang ◽  
...  
Keyword(s):  
Genetic Counseling ◽  
Copy Number ◽  
Genetic Disorders ◽  
Genetic Diagnosis ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Cardiac Defects ◽  
Prenatal Genetic Diagnosis ◽  
Tumor Tissues ◽  
Number Variation

Abstract Background Discordance between traditional cytogenetic and molecular cytogenetic tests is rare but not uncommon. The explanation of discordance between two genetic methods is difficult but especially important for genetic counseling, particularly for prenatal genetic diagnosis. Case presentation Two unrelated fetuses were diagnosed with cardiac defects by prenatal ultrasound examination, and invasive cordocentesis was performed to obtain cord blood samples for prenatal genetic diagnosis. For both fetuses, chromosomal microarray analysis (CMA) detected a novel approximately 27-Mb mosaic duplication with a high copy number of approximately six to seven copies on chromosome 8q24.1q24.3 that was not identified by karyotyping. To exclude artificial errors and validate laboratory detection results, multiple procedures including copy number variation sequencing, fluorescence in situ hybridization, and short tandem repeat and single-nucleotide polymorphism genotype comparison were performed, confirming the discordant results between CMA and karyotyping. The potential causes of discordance between CMA and karyotyping using fetal blood lymphocytes are discussed; we suggest that extrachromosomal DNA or cell-free DNA fragmentation originating from certain tumor tissues with 8q24.1q24.3 duplication might deserve further investigation. Conclusions This study may be helpful for prenatal evaluation and genetic counseling for subsequent patients with similar mosaic 8q24.1q24.3 duplications. Additionally, more cases and further research are needed to understand whether mosaic 8q24.1q24.3 duplication is associated with certain genetic disorders and to investigate the causes of discordance between molecular and morphological methods.

The Promise of Whole-exome Sequencing for Prenatal Genetic Diagnosis

2020 ◽  
Vol 17 (1) ◽  
pp. 25-31
Author(s):  
Jiun Kang
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genetic Disorders ◽  
Genetic Diagnosis ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Prognostic Information ◽  
Prenatal Genetic Diagnosis ◽  
Whole Exome ◽  
Nextgeneration Sequencing

Prenatal genetic diagnosis provides information for pregnancy and perinatal decision- making and management. Cytogenetic testing methods, including chromosomal microarray analysis and gene panels, have evolved to become a part of routine laboratory testing, providing valuable diagnostic and prognostic information for prenatal diagnoses. Despite this progress, however, cytogenetic analyses are limited by their resolution and diagnosis is only possible in around 40% of the dysmorphic fetuses. The advent of nextgeneration sequencing (NGS), whole-genome sequencing or whole-exome sequencing has revolutionized prenatal diagnosis and fetal medicine. These technologies have improved the identification of genetic disorders in fetuses with structural abnormalities and provide valuable diagnostic and prognostic information for the detection of genomic defects. Here, the potential future of prenatal genetic diagnosis, including a move toward NGS technologies, is discussed.

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.

Rapid Diagnosis of Imprinting Disorders Involving Copy Number Variation and Uniparental Disomy Using Genome-Wide SNP Microarrays

2015 ◽  
Vol 146 (1) ◽  
pp. 9-18 ◽  
Author(s):  
Weiqiang Liu ◽  
Rui Zhang ◽  
Jun Wei ◽  
Huimin Zhang ◽  
Guojiu Yu ◽  
...  
Keyword(s):  
Copy Number ◽  
Snp Array ◽  
Uniparental Disomy ◽  
Copy Number Variations ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Imprinting Disorders ◽  
Genome Wide ◽  
Number Variation ◽  
Efficient Alternative

Imprinting disorders, such as Beckwith-Wiedemann syndrome (BWS), Prader-Willi syndrome (PWS) and Angelman syndrome (AS), can be detected via methylation analysis, methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), or other methods. In this study, we applied single nucleotide polymorphism (SNP)-based chromosomal microarray analysis to detect copy number variations (CNVs) and uniparental disomy (UPD) events in patients with suspected imprinting disorders. Of 4 patients, 2 had a 5.25-Mb microdeletion in the 15q11.2q13.2 region, 1 had a 38.4-Mb mosaic UPD in the 11p15.4 region, and 1 had a 60-Mb detectable UPD between regions 14q13.2 and 14q32.13. Although the 14q32.2 region was classified as normal by SNP array for the 14q13 UPD patient, it turned out to be a heterodisomic UPD by short tandem repeat marker analysis. MS-MLPA analysis was performed to validate the variations. In conclusion, SNP-based microarray is an efficient alternative method for quickly and precisely diagnosing PWS, AS, BWS, and other imprinted gene-associated disorders when considering aberrations due to CNVs and most types of UPD.

scholarly journals Peruvian Newborn Male with 3p13 Deletion Syndrome Encompassing the FOXP1 Gene: Review of the Literature

2020 ◽  
Vol 09 (04) ◽  
pp. 270-278
Author(s):  
Hugo H. Abarca-Barriga ◽  
Milana Trubnykova ◽  
Félix Chavesta-Velásquez ◽  
Claudia Barletta-Carrillo ◽  
Marco Ordoñez-Linares ◽  
...  
Keyword(s):  
Copy Number ◽  
Choanal Atresia ◽  
Copy Number Variant ◽  
Autism Spectrum ◽  
Deletion Syndrome ◽  
Chromosomal Microarray ◽  
Facial Dysmorphism ◽  
Chromosomal Microarray Analysis ◽  
Heart Malformation ◽  
Number Variation

AbstractCopy number variation in loss of 3p13 is an infrequently reported entity characterized by hypertelorism, aniridia, microphthalmia, high palate, neurosensorial deafness, camptodactyly, heart malformation, development delay, autism spectrum disorder, seizures, and choanal atresia. The entity is caused probably by haploinsufficiency for FOXP1, UBA3, FAM19A1, and MITF. We report a newborn male with hypotonia, facial dysmorphism, heart malformation, and without clinical diagnosis; nevertheless, the use of appropriate genetic test, such us the chromosomal microarray analysis allowed identification of a copy number variant in loss of 5.5 Mb at chromosome 3 (p13-p14.1), that included 54 genes, encompassing FOXP1 gene. We compare the findings in our Peruvian patient to those of earlier reported patients; furthermore, add new signs for this entity.

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 Chromosomal Abnormality in Fetuses with Isolated Antenatal Hydronephrosis: Update for Prenatal Diagnosis and Genetic Counseling

2020 ◽  
Author(s):  
Xiaoyan Zhou ◽  
Yan Wang ◽  
Lulu Meng ◽  
Jianxin Tan ◽  
Fengchang Qiao ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Chromosomal Abnormalities ◽  
Genetic Diagnosis ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Detection Rates ◽  
Antenatal Hydronephrosis ◽  
Prenatal Genetic Diagnosis ◽  
Group A ◽  
Group B

Abstract Background: The prenatal finding of fetuses with antenatal hydronephrosis (ANH) gives a significant dilemma for the clinicians. Which patients require invasive prenatal diagnosis? Though previous literatures have recommended the use of chromosomal microarray analysis (CMA)for fetuses with CAKUT, the cutoff value for CMA have no current consensus on fetuses with ANH. In this article, we aimed to detect chromosomal abnormalities in fetuses with isolated severe ANH (anterior-posterior renal pelvic diameter (APRPD) ≥ 10mm) by CMA, summarized the literatures and proposed recommendations for the prenatal genetic diagnosis according to APRPD.Methods: Fetuses (n=84) with isolated severe ANH (APRPD ≥ 10mm) were evaluated by CMA. According to APRPD measurements at second trimester, we classified the cases into two groups: (1) Group A: cases with APRPD of 10–15 mm(N=57); (2) Group B: cases with APRPD ≥ 15 mm(N=27).The prenatal and postnatal outcomes were assessed by ultrasonic examination and telephone follow-up.Results: Overall, one case with 18 trisomy was identified. Clinically significant copy number variants (pathogenic or likely pathogenic CNVs) were identified in 11.9% (10/84) cases, including 3.5% (3/84) of pathogenic CNVs. The detection rates were 5.2% (3/57), 25.9% (7/27) for group A and group B, respectively. There was statistically significant differences in the frequency of clinic significant CNVs in the two groups (p＜0.05). Conclusion: CMA is valuable in prenatal genetic diagnosis of fetuses with severe ANH（APRPD ≥ 10mm）, regardless of whether other ultrasonic abnormalities were observed. This cohort should be followed up during the pregnancy.

Osteogenesis Imperfecta and Split Foot Malformation due to 7q21.2q21.3 Deletion Including COL1A2, DLX5/6 Genes: Review of the Literature

2021 ◽  
Author(s):  
Özden Öztürk ◽  
Haydar Bagis ◽  
Semih Bolu
Keyword(s):  
Osteogenesis Imperfecta ◽  
Copy Number ◽  
Bone Fractures ◽  
Genetic Disorder ◽  
Rare Condition ◽  
Copy Number Variant ◽  
Joint Laxity ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Number Variation

AbstractCopy number variation in loss of 7q21 is a genetic disorder characterized by split hand/foot malformation, hearing loss, developmental delay, myoclonus, dystonia, joint laxity, and psychiatric disorders. Osteogenesis imperfecta caused by whole gene deletions of COL1A2 is a very rare condition. We report a Turkish girl with ectrodactyly, joint laxity, multiple bone fractures, blue sclera, early teeth decay, mild learning disability, and depression. A copy number variant in loss of 4.8 Mb at chromosome 7 (q21.2q21.3) included the 58 genes including DLX5, DLX6, DYNC1I1, SLC25A13, SGCE, and COL1A2. They were identified by chromosomal microarray analysis. We compared the findings in our patients with those previously reported. This case report highlights the importance of using microarray to identify the genetic etiology in patients with ectrodactyly and osteogenesis imperfecta.

scholarly journals Difficulties of Prenatal Genetic Counseling for a Subsequent Child in a Family With Multiple Genetic Variations

2021 ◽  
Vol 12 ◽  
Author(s):  
Ting-Xuan Huang ◽  
Gwo-Chin Ma ◽  
Ming Chen ◽  
Wen-Fang Li ◽  
Steven W. Shaw
Keyword(s):  
Genetic Counseling ◽  
De Novo ◽  
Genetic Diagnosis ◽  
Genetic Variations ◽  
Epileptic Encephalopathy ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Prenatal Counseling ◽  
Ethical Implications ◽  
Genome Wide

Many parents with a disabled child caused by a genetic condition appreciate the option of prenatal genetic diagnosis to understand the chance of recurrence in a future pregnancy. Genome-wide tests, such as chromosomal microarray analysis and whole-exome sequencing, have been increasingly used for prenatal diagnosis, but prenatal counseling can be challenging due to the complexity of genomic data. This situation is further complicated by incidental findings of additional genetic variations in subsequent pregnancies. Here, we report the prenatal identification of a baby with a MECP2 missense variant and 15q11.2 microduplication in a family that has had a child with developmental and epileptic encephalopathy caused by a de novo KCNQ2 variant. An extended segregation analysis including extended relatives, in addition to the parents, was carried out to provide further information for genetic counseling. This case illustrates the challenges of prenatal counseling and highlights the need to understand the clinical and ethical implications of genome-wide tests.

scholarly journals Integrated CNV-seq, karyotyping and SNP-array analyses for effective prenatal diagnosis of chromosomal mosaicism

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Na Ma ◽  
Hui Xi ◽  
Jing Chen ◽  
Ying Peng ◽  
Zhengjun Jia ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Sex Chromosome ◽  
Snp Array ◽  
Genomic Rearrangements ◽  
Chromosomal Mosaicism ◽  
Chromosomal Microarray ◽  
Chromosomal Microarray Analysis ◽  
Low Level ◽  
Autosomal Aneuploidy ◽  
Number Variation

Abstract Background Emerging studies suggest that low‐coverage massively parallel copy number variation sequencing (CNV-seq) more sensitive than chromosomal microarray analysis (CMA) for detecting low-level mosaicism. However, a retrospective back-to-back comparison evaluating accuracy, efficacy, and incremental yield of CNV-seq compared with CMA is warranted. Methods A total of 72 mosaicism cases identified by karyotyping or CMA were recruited to the study. There were 67 mosaic samples co-analysed by CMA and CNV-seq, comprising 40 with sex chromosome aneuploidy, 22 with autosomal aneuploidy and 5 with large cryptic genomic rearrangements. Results Of the 67 positive mosaic cases, the levels of mosaicism defined by CNV-seq ranged from 6 to 92% compared to the ratio from 3 to 90% by karyotyping and 20% to 72% by CMA. CNV-seq not only identified all 43 chromosomal aneuploidies or large cryptic genomic rearrangements detected by CMA, but also provided a 34.88% (15/43) increased yield compared with CMA. The improved yield of mosaicism detection by CNV-seq was largely due to the ability to detect low level mosaicism below 20%. Conclusion In the context of prenatal diagnosis, CNV-seq identified additional and clinically significant mosaicism with enhanced resolution and increased sensitivity. This study provides strong evidence for applying CNV-seq as an alternative to CMA for detection of aneuploidy and mosaic variants.

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