scholarly journals Spontaneous mutations and transmission distortions of genic copy number variants shape the standing genetic variation in Picea glauca

2017 ◽  
Author(s):  
Atef Sahli ◽  
Isabelle Giguére ◽  
Jean Bousquet ◽  
John MacKay
Keyword(s):  
Genetic Variation ◽  
Picea Glauca ◽  
Copy Number ◽  
De Novo ◽  
Snp Array ◽  
Copy Number Variations ◽  
Spontaneous Mutations ◽  
Evolutionary Forces ◽  
Gene Space ◽  
Transmission Distortions

AbstractCopy number variations (CNVs) are large genetic variations detected among the individuals of every multicellular organism examined so far. These variations are believed to play an important role in the evolution and adaptation of species. In plants, little is known about the characteristics of CNVs, particularly regarding the rates at which they are generated and the mechanics of their transmission from a generation to the next. Here, we used SNP-array raw intensity data for 55 two-generations families (3663 individuals) to scan the gene space of the conifer tree Picea glauca (Moench) Voss for CNVs. We were particularly interested in the abundance, inheritance, spontaneous mutation rate spectrum and the evolutionary consequences they may have on the standing genetic variation of white spruce. Our findings show that CNVs affect a small proportion of the gene space and are predominantly copy number losses. CNVs were either inherited or generated through de novo events. De novo CNVs present high rates of spontaneous mutations that vary for different genes and alleles and are correlated with gene expression levels. Most of the inherited CNVs (70%) are transmitted from the parents in violation of Mendelian expectations. These transmission distortions can cause considerable frequency changes between generations and be dependent on whether the heterozygote parents contribute as male or female. Transmission distortions were also influenced by the partner genotype and the parents’ genetic background. This study provides new insights into the effects of different evolutionary forces on copy number variations based on the analysis of a perennial plant.

scholarly journals The Cytoscan HD Array in the Diagnosis of Neurodevelopmental Disorders

2018 ◽  
Vol 7 (3) ◽  
pp. 28 ◽  
Author(s):  
Francesca Scionti ◽  
Maria Di Martino ◽  
Licia Pensabene ◽  
Valentina Bruni ◽  
Daniela Concolino
Keyword(s):  
Copy Number ◽  
De Novo ◽  
Snp Array ◽  
Autism Spectrum ◽  
Copy Number Variations ◽  
Clinical Diagnostic Laboratory ◽  
Diagnostic Laboratory ◽  
Unknown Significance ◽  
Pathogenic Cnvs ◽  
Line Test

Submicroscopic chromosomal copy number variations (CNVs), such as deletions and duplications, account for about 15–20% of patients affected with developmental delay, intellectual disability, multiple congenital anomalies, and autism spectrum disorder. Most of CNVs are de novo or inherited rearrangements with clinical relevance, but there are also rare inherited imbalances with unknown significance that make difficult the clinical management and genetic counselling. Chromosomal microarrays analysis (CMA) are recognized as the first-line test for CNV detection and are now routinely used in the clinical diagnostic laboratory. The recent use of CMA platforms that combine classic copy number analysis with single-nucleotide polymorphism (SNP) genotyping has increased the diagnostic yields. Here we discuss the application of the Cytoscan high-density (HD) SNP-array for the detection of CNVs. We provide an overview of molecular analyses involved in identifying pathogenic CNVs and highlight important guidelines to establish pathogenicity of CNV.

scholarly journals Lessons Learned from CNV Analysis of Major Birth Defects

2020 ◽  
Vol 21 (21) ◽  
pp. 8247
Author(s):  
Alina Christine Hilger ◽  
Gabriel Clemens Dworschak ◽  
Heiko Martin Reutter
Keyword(s):  
Birth Defects ◽  
Copy Number ◽  
Congenital Malformations ◽  
De Novo ◽  
Copy Number Variations ◽  
Lessons Learned ◽  
Organ System ◽  
Molecular Karyotyping ◽  
The Past ◽  
Single Organ

The treatment of major birth defects are key concerns for child health. Hitherto, for the majority of birth defects, the underlying cause remains unknown, likely to be heterogeneous. The implicated mortality and/or reduced fecundity in major birth defects suggest a significant fraction of mutational de novo events among the affected individuals. With the advent of systematic array-based molecular karyotyping, larger cohorts of affected individuals have been screened over the past decade. This review discusses the identification of disease-causing copy-number variations (CNVs) among individuals with different congenital malformations. It highlights the differences in findings depending on the respective congenital malformation. It looks at the differences in findings of CNV analysis in non-isolated complex congenital malformations, associated with central nervous system malformations or intellectual disabilities, compared to isolated single organ-system malformations. We propose that the more complex an organ system is, and the more genes involved during embryonic development, the more likely it is that mutational de novo events, comprising CNVs, will confer to the expression of birth defects of this organ system.

scholarly journals A Case With 4 de Novo Copy Number Variations With Clinical Features That Overlap 1q43q44 Microdeletion and 3q29 Microduplication Syndromes

2018 ◽  
Vol 5 ◽  
pp. 2329048X1879820
Author(s):  
Miriam Kessi ◽  
Jing Peng ◽  
Lifen Yang ◽  
Haolin Duan ◽  
Yulin Tang ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Corpus Callosum ◽  
Copy Number ◽  
De Novo ◽  
Copy Number Variations ◽  
Language Delay ◽  
Global Developmental Delay ◽  
Recurrent Infections ◽  
Dental Anomalies ◽  
Microdeletion Syndrome

1q43q44 microdeletion syndrome is characterized by intellectual disability/global developmental delay, epilepsy, dysmorphic facies, stereotypic movement, language delay, recurrent infections, dental anomalies, and hand and foot anomalies. Microcephaly and corpus callosum dysplasia are present in some cases depending on gene content. 3q29 microduplication syndrome is characterized by intellectual disability, language delay, microcephaly, and dental anomalies. We report the first case with 4 de novo copy number variations with clinical features which overlap 1q43q44 microdeletion and 3q29 microduplication syndromes. Our case presented with global developmental delay, epilepsy, recurrent infections, stereotypic movements, speech delay, microcephaly, facial dysmorphism, bilateral clinodactyly, and small puffy feet with metatarsus varus; however, she had no corpus callosum dysplasia. Our case highlights the role of multiple copy number variations in the occurrence of a certain phenotype. Moreover, it supports the theory that the loss of HNRNPU gene function cannot explain the occurrence of microcephaly and abnormalities of the corpus callosum in 1q43q44 microdeletion syndrome.

scholarly journals Integrating genomic correlation structure improves copy number variations detection

2020 ◽  
Author(s):  
Xizhi Luo ◽  
Fei Qin ◽  
Guoshuai Cai ◽  
Feifei Xiao
Keyword(s):  
Copy Number ◽  
Snp Array ◽  
Copy Number Variations ◽  
Correlation Structure ◽  
Supplementary Information ◽  
Dependence Structure ◽  
Random Pattern ◽  
Genomic Correlation ◽  
Equal Chance ◽  
Cnv Detection

Abstract Motivation Copy number variation plays important roles in human complex diseases. The detection of copy number variants (CNVs) is identifying mean shift in genetic intensities to locate chromosomal breakpoints, the step of which is referred to as chromosomal segmentation. Many segmentation algorithms have been developed with a strong assumption of independent observations in the genetic loci, and they assume each locus has an equal chance to be a breakpoint (i.e. boundary of CNVs). However, this assumption is violated in the genetics perspective due to the existence of correlation among genomic positions, such as linkage disequilibrium (LD). Our study showed that the LD structure is related to the location distribution of CNVs, which indeed presents a non-random pattern on the genome. To generate more accurate CNVs, we proposed a novel algorithm, LDcnv, that models the CNV data with its biological characteristics relating to genetic dependence structure (i.e. LD). Results We theoretically demonstrated the correlation structure of CNV data in SNP array, which further supports the necessity of integrating biological structure in statistical methods for CNV detection. Therefore, we developed the LDcnv that integrated the genomic correlation structure with a local search strategy into statistical modeling of the CNV intensities. To evaluate the performance of LDcnv, we conducted extensive simulations and analyzed large-scale HapMap datasets. We showed that LDcnv presented high accuracy, stability and robustness in CNV detection and higher precision in detecting short CNVs compared to existing methods. This new segmentation algorithm has a wide scope of potential application with data from various high-throughput technology platforms. Availability and implementation https://github.com/FeifeiXiaoUSC/LDcnv. Supplementary information Supplementary data are available at Bioinformatics online.

High-Resolution Genomic Profiling of Philadelphia Chromosome-Positive (Ph+) Acute Lymphoblastic Leukaemia (ALL) Identified Novel Recurrent Copy Number Variations Involved in Both Pathogenesis and Resistance to Tyrosine Kinase Inhibitors.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 230-230
Author(s):  
Ilaria Iacobucci ◽  
E. Ottaviani ◽  
A. Astolfi ◽  
S. Soverini ◽  
N. Testoni ◽  
...  
Keyword(s):  
High Resolution ◽  
Copy Number ◽  
Complex Disease ◽  
B Lymphocyte ◽  
Philadelphia Chromosome ◽  
Snp Array ◽  
Copy Number Variations ◽  
Imatinib Resistance ◽  
Copy Number State ◽  
Monosomy 7

Abstract The Ph chromosome is the most frequent cytogenetic aberration associated with ALL and it represents the single most significant adverse prognostic marker. Despite the encouraging results achieved with imatinib, resistance develops rapidly and is quickly followed by disease progression. Some mechanisms of resistance have been widely described but the full knowledge of contributing factors driving both the disease and resistance remains to be defined. In order to identify at submicroscopic level genetic lesions driving leukemogenesis and resistance, we profiled until now the genomes of 18 patients, out of 55 Ph+ ALL patients treated in our institute, at diagnosis (n=11) or at the time of haematological relapse (n=7) during therapy with imatinib or dasatinib. 250 ng of genomic DNA were processed on 500K single nucleotide polymorphism (SNP) array according to protocols provided by the manufacturer (Affymetrix Inc., Santa Clara, CA, USA). The median SNP call rate of analysed samples was 96%. Raw signal data were analyzed by BRLMM algorithm and copy number state was calculated with respect to a set of 48 Hapmap normal individuals and a diploid reference set of samples obtained from acute leukaemia cases in remission. Regions of amplification and deletion were visualized by Integrated Genome Browser and mapped to RefSeq to identify the specific genes involved in the lesion. Our analysis identified multiple copy number alterations per case, with deletions outnumbering amplification almost 3:1. Lesions varied from loss or gain of complete chromosome arms (trisomy 4, monosomy 7, loss of 9p, 10q, 14q, 16q and gain of 1q and 17q) to microdeletions and microduplications targeting genomic intervals. The recurring microdeletions that we detected in at least 50% of patients (both at diagnosis and at relapse) included 1p36.21 (PRAMEF), 3q29 (TFCR), 7p14.1 (AMPH), 8p23 (DEFB105A), 14q11.2 (DAD1), 16p13.11 (PDXDC1, NTAN1, RRN3), 16p11.2 (SNP) and 19p13.2 (CARM1, SMARCA4). A common microamplification was 4q13.2 (TMPRSS11E) and 17q21.31. Some genomic alterations were identified in genes regulating B-lymphocyte differentiation, such as PAX5 (n=3), BLNK (n=1) and VPREB1 (n=6) and in genes with an established role in leukemogenesis, such as MDS, BTG1, MLLT3 and RUNX1. Furthermore, many of the deletions detected included genes encoded for phosphatase proteins (e.g. PTPRD, PPP1R9B, PTPN18) and for zinc-finger proteins without any difference between diagnosis and resistance. It is noteworthy that some lesions felt in regions lacking annotated genes (loss: 2p11.2, 3p12.3, 7q11.21 and 14q32.33; gain: 8q23.3 and 13q21.1). Using high-resolution genome wide approach we showed that Ph+ ALL is a more complex disease characterized by multiple genomic anomalies which may provide new insights into the mechanisms underlying leukemogenesis and may be used as targets for existing or novel drugs. Supported by: European LeukemiaNet, COFIN 2003, Novartis Oncology Clinical Development, AIL.

scholarly journals Characteristics of Highly Polymorphic Segmental Copy-Number Variations Observed in Japanese by BAC-Array-CGH

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Norio Takahashi ◽  
Yasunari Satoh ◽  
Keiko Sasaki ◽  
Yuko Shimoichi ◽  
Keiko Sugita ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Copy Number ◽  
Array Cgh ◽  
Artificial Chromosome ◽  
Copy Number Variations ◽  
Comparative Genomic ◽  
Bac Clones ◽  
Japanese Cohort ◽  
The Individual ◽  
Chromosome Microarray

Segmental copy-number variations (CNVs) may contribute to genetic variation in humans. Reports of the existence and characteristics of CNVs in a large Japanese cohort are quite limited. We report the data from a large Japanese population. We conducted population screening for 213 unrelated Japanese individuals using comparative genomic hybridization based on a bacterial artificial chromosome microarray (BAC-aCGH). We summarize the data by focusing on highly polymorphic CNVs in ≥5.0% of the individual, since they may be informative for demonstrating the relationships between genotypes and their phenotypes. We found a total of 680 CNVs at 16 different BAC-regions in the genome. The majority of the polymorphic CNVs presented on BAC-clones that overlapped with regions of segmental duplication, and the majority of the polymorphic CNVs observed in this population had been previously reported in other publications. Some of the CNVs contained genes which might be related to phenotypic heterogeneity among individuals.

scholarly journals Associations between Familial Rates of Psychiatric Disorders and De Novo Genetic Mutations in Autism

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Kyleen Luhrs ◽  
Tracey Ward ◽  
Caitlin M. Hudac ◽  
Jennifer Gerdts ◽  
Holly A. F. Stessman ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Copy Number ◽  
Depressive Disorders ◽  
De Novo ◽  
Familial Risk ◽  
Autism Spectrum ◽  
Copy Number Variations ◽  
Genetic Etiology ◽  
Additive Contribution ◽  
Familial Risk Factors

The purpose of this study was to examine the confluence of genetic and familial risk factors in children with Autism Spectrum Disorder (ASD) with distinct de novo genetic events. We hypothesized that gene-disrupting mutations would be associated with reduced rates of familial psychiatric disorders relative to structural mutations. Participants included families of children with ASD in four groups: de novo duplication copy number variations (DUP, n=62), de novo deletion copy number variations (DEL, n=74), de novo likely gene-disrupting mutations (LGDM, n=267), and children without a known genetic etiology (NON, n=2111). Familial rates of psychiatric disorders were calculated from semistructured interviews. Results indicated overall increased rates of psychiatric disorders in DUP families compared to DEL and LGDM families, specific to paternal psychiatric histories, and particularly evident for depressive disorders. Higher rates of depressive disorders in maternal psychiatric histories were observed overall compared to paternal histories and higher rates of anxiety disorders were observed in paternal histories for LGDM families compared to DUP families. These findings support the notion of an additive contribution of genetic etiology and familial factors are associated with ASD risk and highlight critical need for continued work targeting these relationships.

scholarly journals Clinical Utility and the Yield of Single Nucleotide Polymorphism Array in Prenatal Diagnosis of Fetal Central Nervous System Abnormalities

2021 ◽  
Vol 8 ◽  
Author(s):  
Meiying Cai ◽  
Hailong Huang ◽  
Liangpu Xu ◽  
Na Lin
Keyword(s):  
Central Nervous System ◽  
Single Nucleotide Polymorphism ◽  
Copy Number ◽  
Chromosomal Abnormalities ◽  
Karyotype Analysis ◽  
Snp Array ◽  
Copy Number Variations ◽  
Nucleotide Polymorphism ◽  
Single Nucleotide ◽  
Pathogenic Cnvs

Applying single nucleotide polymorphism (SNP) array to identify the etiology of fetal central nervous system (CNS) abnormality, and exploring its association with chromosomal abnormalities, copy number variations, and obstetrical outcome. 535 fetuses with CNS abnormalities were analyzed using karyotype analysis and SNP array. Among the 535 fetuses with CNS abnormalities, chromosomal abnormalities were detected in 36 (6.7%) of the fetuses, which were consistent with karyotype analysis. Further, additional 41 fetuses with abnormal copy number variations (CNVs) were detected using SNP array (the detection rate of additional abnormal CNVs was 7.7%). The rate of chromosomal abnormalities, but not that of pathogenic CNVs in CNS abnormalities with other ultrasound abnormalities was significantly higher than that in isolated CNS abnormalities. The rates of chromosomal abnormalities and pathogenic CNVs in fetuses with spine malformation (50%), encephalocele (50%), subependymal cyst (20%), and microcephaly (16.7%) were higher than those with other isolated CNS abnormalities. The pregnancies for 36 cases with chromosomal abnormalities, 18 cases with pathogenic CNVs, and three cases with VUS CNVs were terminated. SNP array should be used in the prenatal diagnosis of fetuses with CNS abnormalities, which can enable better prenatal assessment and genetic counseling, and affect obstetrical outcomes.

scholarly journals Evaluation of Chromosomal Abnormalities and Copy Number Variations in Fetuses with Ultrasonic Soft Markers

2020 ◽  
Author(s):  
Meiying Cai ◽  
Na Lin ◽  
Liangpu Xu ◽  
hailong huang
Keyword(s):  
Copy Number ◽  
Chromosomal Abnormalities ◽  
Snp Array ◽  
Copy Number Variations ◽  
Clinical Value ◽  
Obstetrical Outcomes ◽  
Genetic Abnormalities ◽  
Significant Difference ◽  
Snp Array Analysis ◽  
Soft Marker

Abstract Background: Some ultrasonic soft markers can be found during ultrasound examination. However, the etiology of the fetuses with ultrasonic soft markers is still unknown. This study aimed to evaluate the genetic etiology and clinical value of chromosomal abnormalities and copy number variations (CNVs) in fetuses with ultrasonic soft markers.Methods: Among 1131 fetuses, 729 had single ultrasonic soft marker, 322 had two ultrasonic soft markers, and 80 had three or more ultrasonic soft markers. All fetuses underwent conventional karyotyping, followed by single nucleotide polymorphism (SNP) array analysis. Results: Among 1131 fetuses with ultrasonic soft markers, 46 had chromosomal abnormalities. In addition to the 46 fetuses with chromosomal abnormalities consistent with the results of the karyotyping analysis, the SNP array identified additional 6.1% (69/1131) abnormal CNVs. The rate of abnormal CNVs in fetuses with ultrasonic soft marker, two ultrasonic soft markers, three or more ultrasonic soft markers were 6.2%, 6.2%, and 5.0%, respectively. No significant difference was found in the rate of abnormal CNVs among the groups.Conclusions: Genetic abnormalities affect obstetrical outcomes. The SNP array can fully complement conventional karyotyping in fetuses with ultrasonic soft markers, improve detection rate of chromosomal abnormalities, and affect obstetrical outcomes.

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