scholarly journals GATA2 deficiency phenotype associated with tandem duplication GATA2 and over-expression of GATA2-AS1

2021 ◽  
Author(s):  
Preeti Singh ◽  
Maninder Heer ◽  
Anastasia Resteu ◽  
Aneta Mikulasova ◽  
Mojgan Reza ◽  
...  
Keyword(s):  
De Novo ◽  
Blood Analysis ◽  
Mediastinal Lymphadenopathy ◽  
Mycobacterium Fortuitum ◽  
Intronic Enhancer ◽  
Frameshift Deletion ◽  
Number Variation ◽  
Gata2 Deficiency ◽  
Chimeric Rna ◽  
Allele Count

A 3-year old girl of non-consanguineous healthy parents presented with cervical and mediastinal lymphadenopathy due to Mycobacterium fortuitum infection. Routine blood analysis showed normal hemoglobin, neutrophils and platelets but profound mononuclear cell deficiency (monocytes <0.1x109/L; B cells 78/µL; NK cells 48/µL). A 548,902bp region containing GATA2 was sequenced by targeted capture and deep sequencing. This revealed a de novo 187Kb duplication of the entire GATA2 locus, containing a maternally inherited copy number variation deletion of 25Kb (GRCh37: esv2725896 and nsv513733). Many GATA2-associated phenotypes have been attributed to amino acid substitution, frameshift/deletion, loss of intronic enhancer function or aberrant splicing. Gene deletion has been described but other structural variation has not been reported in the germline configuration. In this case, duplication of the GATA2 locus was paradoxically associated with skewed, diminished expression of GATA2 mRNA and loss of GATA2 protein. Chimeric RNA fusion transcripts were not detected. A possible mechanism involves increased transcription of the anti-sense long-non-coding (lnc)RNA GATA2-AS1 (RP11-472.220) which was increased several-fold. This case further highlights that evaluation of the allele count is essential in any case of suspected GATA2-related syndrome.

scholarly journals Insights into dispersed duplications and complex structural mutations from whole genome sequencing 706 families

2020 ◽  
Author(s):  
Christopher W. Whelan ◽  
Robert E. Handsaker ◽  
Giulio Genovese ◽  
Seva Kashin ◽  
Monkol Lek ◽  
...  
Keyword(s):  
Gene Expression ◽  
Copy Number Variation ◽  
Copy Number ◽  
De Novo ◽  
Whole Genome ◽  
Sequencing Data ◽  
Number Variation ◽  
Structural Mutations ◽  
Or Gene ◽  
Genomic Locations

AbstractTwo intriguing forms of genome structural variation (SV) – dispersed duplications, and de novo rearrangements of complex, multi-allelic loci – have long escaped genomic analysis. We describe a new way to find and characterize such variation by utilizing identity-by-descent (IBD) relationships between siblings together with high-precision measurements of segmental copy number. Analyzing whole-genome sequence data from 706 families, we find hundreds of “IBD-discordant” (IBDD) CNVs: loci at which siblings’ CNV measurements and IBD states are mathematically inconsistent. We found that commonly-IBDD CNVs identify dispersed duplications; we mapped 95 of these common dispersed duplications to their true genomic locations through family-based linkage and population linkage disequilibrium (LD), and found several to be in strong LD with genome-wide association (GWAS) signals for common diseases or gene expression variation at their revealed genomic locations. Other CNVs that were IBDD in a single family appear to involve de novo mutations in complex and multi-allelic loci; we identified 26 de novo structural mutations that had not been previously detected in earlier analyses of the same families by diverse SV analysis methods. These included a de novo mutation of the amylase gene locus and multiple de novo mutations at chromosome 15q14. Combining these complex mutations with more-conventional CNVs, we estimate that segmental mutations larger than 1kb arise in about one per 22 human meioses. These methods are complementary to previous techniques in that they interrogate genomic regions that are home to segmental duplication, high CNV allele frequencies, and multi-allelic CNVs.Author SummaryCopy number variation is an important form of genetic variation in which individuals differ in the number of copies of segments of their genomes. Certain aspects of copy number variation have traditionally been difficult to study using short-read sequencing data. For example, standard analyses often cannot tell whether the duplicated copies of a segment are located near the original copy or are dispersed to other regions of the genome. Another aspect of copy number variation that has been difficult to study is the detection of mutations in the copy number of DNA segments passed down from parents to their children, particularly when the mutations affect genome segments which already display common copy number variation in the population. We develop an analytical approach to solving these problems when sequencing data is available for all members of families with at least two children. This method is based on determining the number of parental haplotypes the two siblings share at each location in their genome, and using that information to determine the possible inheritance patterns that might explain the copy numbers we observe in each family member. We show that dispersed duplications and mutations can be identified by looking for copy number variants that do not follow these expected inheritance patterns. We use this approach to determine the location of 95 common duplications which are dispersed to distant regions of the genome, and demonstrate that these duplications are linked to genetic variants that affect disease risk or gene expression levels. We also identify a set of copy number mutations not detected by previous analyses of sequencing data from a large cohort of families, and show that repetitive and complex regions of the genome undergo frequent mutations in copy number.

scholarly journals A novel 14q13.1–21.1 deletion identified by CNV-Seq in a patient with brain-lung-thyroid syndrome, tooth agenesis and immunodeficiency

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Xuyun Hu ◽  
Jun Liu ◽  
Ruolan Guo ◽  
Jun Guo ◽  
Zhipeng Zhao ◽  
...  
Keyword(s):  
De Novo ◽  
Deletion Syndrome ◽  
Tooth Agenesis ◽  
Diagnostic Strategy ◽  
Genomic Disorder ◽  
Case Presentation ◽  
Whole Exome ◽  
Number Variation ◽  
Phenotype Heterogeneity ◽  
Genomic Disorders

Abstract Background Chromosome 14q11-q22 deletion syndrome (OMIM 613457) is a rare genomic disorder. The phenotype heterogeneity depends on the deletion size, breakpoints and genes deleted. Critical genes like FOXG1, NKX2–1, PAX9 were identified. Case presentation We performed whole exome sequencing (WES) and copy number variation sequencing (CNV-seq) for a patient with mild speech and motor developmental delay, short stature, recurrent pulmonary infections, tooth agenesis and triad of brain-lung-thyroid syndrome. By using CNV-seq, we identified a 3.1 Mb de novo interstitial deletion of the 14q13.2q21.1 region encompassing 17 OMIM genes including NKX2–1, PAX9 and NFKBIA. Our patient’s phenotype is consistent with other published 14q13 deletion patients. Conclusion Our results showed the combination of WES and CNV-seq is an effective diagnostic strategy for patients with genetic or genomic disorders. After reviewing published patients, we also proposed a new critical region for 14q13 deletion syndrome with is a more benign disorder compared to 14q11-q22 deletion syndrome.

scholarly journals Limited role of differential fractionation in genome content variation and function in maize (Zea mays L.) inbred lines

2017 ◽  
Author(s):  
Alex B. Brohammer ◽  
Thomas JY. Kono ◽  
Nathan M. Springer ◽  
Suzanne E. McGaugh ◽  
Candice N. Hirsch
Keyword(s):  
Large Scale ◽  
De Novo ◽  
Duplicate Gene ◽  
Duplication Event ◽  
Inbred Lines ◽  
Whole Genome ◽  
Ancestral State ◽  
Genome Duplication Event ◽  
Number Variation ◽  
And Function

SUMMARYMaize is a diverse paleotetraploid species with widespread presence/absence variation and copy number variation. One mechanism through which presence/absence variation can arise is differential fractionation. Fractionation refers to the loss of duplicate gene pairs from one of the maize subgenomes during diploidization and differential fractionation refers to non-shared gene loss events between individuals. We investigated the prevalence of presence/absence variation resulting from differential fractionation in the syntenic portion of the genome using two whole genome de novo assemblies of the inbred lines B73 and PH207. Between these two genomes, syntenic genes were highly conserved with less than 1% of syntenic genes being subject to differential fractionation. The few variable syntenic genes that were identified are unlikely to contribute to functional phenotypic variation, as there is a significant depletion of these genes in annotated gene sets. In further comparisons of 60 diverse inbred lines, non-syntenic genes were six times more likely to be variable compared to syntenic genes, suggesting that comparisons among additional genome assemblies are not likely to result in the discovery of large-scale presence/absence variation among syntenic genes.SIGNIFICANCE STATEMENTThere is a large amount of presence/absence variation for gene content in maize. One mechanism that has been hypothesized to contribute to this variation is differential fractionation between individuals following the maize whole genome duplication event. Using comparative genomics, with sorghum and rice representing the ancestral state, we observed little evidence of differential fractionation among elite inbred lines and the few differentially fractionated genes identified did not appear to confer functional significance.

scholarly journals Ethical and public policy challenges for pharmacogenomics

2014 ◽  
Vol 16 (4) ◽  
pp. 567-574 ◽  
Keyword(s):  
Psychiatric Disorders ◽  
Large Scale ◽  
Ethical Issues ◽  
De Novo ◽  
Correct Choice ◽  
Genomic Research ◽  
Drug Metabolizing Enzyme ◽  
Increased Risk ◽  
Number Variation ◽  
Metabolizing Enzyme

It is timely to consider the ethical and social questions raised by progress in pharmacogenomics, based on the current importance of pharmacogenomics for avoidance of predictable side effects of drugs, and for correct choice of medications in certain cancers. It has been proposed that the entire population be genotyped for drug-metabolizing enzyme polymorphisms, as a measure that would prevent many untoward and dangerous drug reactions. Pharmacologic treatment targeting based on genomics of disease can be expected to increase greatly in the coming years. Policy and ethical issues exist on consent for large-scale genomic pharmacogenomic data collection, public vs corporate ownership of genomic research results, testing efficacy and safety of drugs used for rare genomic indications, and accessibility of treatments based on costly research that is applicable to relatively few patients. In major psychiatric disorders and intellectual deficiency, rare and de novo deletion or duplication of chromosomal segments (copy number variation), in the aggregate, are common causes of increased risk. This implies that the policy problems of pharmacogenomics will be particularly important for the psychiatric disorders.

scholarly journals Case Report: Identification of a de novo Microdeletion 1q44 in a Patient With Seizures and Developmental Delay

2021 ◽  
Vol 12 ◽  
Author(s):  
Yiehen Tung ◽  
Haiying Lu ◽  
Wenxin Lin ◽  
Tingting Huang ◽  
Samuel Kim ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
Clinical Symptoms ◽  
Karyotype Analysis ◽  
Microdeletion Syndrome ◽  
Phenotypic Spectrum ◽  
Whole Exome ◽  
Number Variation ◽  
History Of

Objective: 1q44 microdeletion syndrome is difficult to diagnose due to the wide phenotypic spectrum and strong genetic heterogeneity. We explore the correlation between the chromosome microdeletions and phenotype in a child with 1q44 microdeletion syndrome, we collected the clinical features of the patient and combined them with adjacent copy number variation (CNV) regions previously reported.Methods: We collected the full medical history of the patient and summarized her clinical symptoms. Whole-exome sequencing (WES) and CapCNV analysis were performed with DNA extracted from both the patient's and her parents' peripheral blood samples. Fluorescent quantitative PCR (q-PCR) was performed for the use of verification to the CNV regions.Results: A 28.7 KB microdeletion was detected in the 1q44 region by whole-exome sequencing and low-depth whole-genome sequencing. The deleted region included the genes COX20 and HNRNPU. As verification, karyotype analysis showed no abnormality, and the results of qPCR were consistent with that of whole-exome sequencing and CapCNV analysis.Conclusion: The patient was diagnosed with 1q44 microdeletion syndrome with clinical and genetic analysis. Analyzing both whole-exome sequencing and CapCNV analysis can not only improve the diagnostic rate of clinically suspected syndromes that present with intellectual disability (ID) and multiple malformations but also support further study of the correlation between CNVs and clinical phenotypes. This study lays the foundation for the further study of the pathogenesis of complex diseases.

scholarly journals Molecular Delineation of De Novo Small Supernumerary Marker Chromosomes in Prenatal Diagnosis, A Retrospective Study

2021 ◽  
Author(s):  
Shuang Hu ◽  
Xiangdong Kong
Keyword(s):  
Genetic Counseling ◽  
Prenatal Diagnosis ◽  
De Novo ◽  
Snp Array ◽  
Chromosome 9 ◽  
Marker Chromosomes ◽  
Number Variation ◽  
Low Coverage ◽  
Small Supernumerary Marker Chromosomes ◽  
Supernumerary Marker Chromosomes

Abstract Background To define the genotype-phenotype correlation of small supernumerary marker chromosomes (sSMCs) and conduct precise genetic counseling, we retrospectively searched and reviewed de novo sSMC cases detected during prenatal diagnosis at The First Affiliated Hospital of Zhengzhou University. Chromosome karyotypes of 20,314 cases of amniotic fluid from pregnant women were performed. For 16 samples with de novo sSMCs, 10 were subjected to single-nucleotide polymorphism (SNP) array or low-coverage massively parallel copy number variation sequencing (CNV-seq) analysis. Results Among the 10 sSMC cases, two sSMCs derived from chromosome 9, and three sSMCs derived from chromosomes 12, 18 and 22. The remaining 5 cases were not identified by SNP array or CNV-seq because they lacked euchromatin or had a low proportion of mosaicism. Four of them with a karyotype of 47,XN,+mar presented normal molecular cytogenetic results (seq[hg19] 46,XN), and the remaining patient with a karyotype of 46,XN,+mar presented with Turner syndrome (seq[hg19] 45,X). Five sSMC samples were mosaics of all 16 cases. Conclusion Considering the variable origins of sSMCs, further genetic testing of sSMCs should be performed by SNP array or CNV-seq. Detailed molecular characterization would allow precise genetic counseling for prenatal diagnosis.

scholarly journals Synaptonemal complex-deficient Drosophila melanogaster females exhibit rare DSB repair events, recurrent copy number variation, and an increased rate of de novo transposable element movement

2019 ◽  
Author(s):  
Danny E. Miller
Keyword(s):  
Drosophila Melanogaster ◽  
Copy Number Variation ◽  
Transposable Element ◽  
Synaptonemal Complex ◽  
Copy Number ◽  
De Novo ◽  
Wild Type ◽  
Dsb Repair ◽  
Number Variation ◽  
Element Movement

ABSTRACTGenetic stability depends on the maintenance of a variety of chromosome structures and the precise repair of DNA breaks. During meiosis, programmed double-strand breaks (DSBs) made in prophase I are normally repaired as gene conversions or crossovers. Additionally, DSBs are made by the movement of transposable elements (TEs), which must also be resolved. Incorrect repair of these DNA lesions can lead to mutations, copy number variations, translocations, and/or aneuploid gametes. In Drosophila melanogaster, as in most organisms, meiotic DSB repair occurs in the presence of a rapidly evolving multiprotein structure called the synaptonemal complex (SC). Here, whole-genome sequencing is used to investigate the fate of meiotic DSBs in D. melanogaster mutant females lacking functional SC, to assay for de novo CNV formation, and to examine the role of the SC in transposable element movement in flies. The data indicate that, in the absence of SC, copy number variation still occurs but meiotic DSB repair by gene conversion may occur only rarely. Remarkably, an 856-kilobase de novo CNV was observed in two unrelated individuals of different genetic backgrounds and was identical to a CNV recovered in a previous wild-type study, suggesting that recurrent formation of large CNVs occurs in Drosophila. In addition, the rate of novel TE insertion was markedly higher than wild type in one of two SC mutants tested, suggesting that SC proteins may contribute to the regulation of TE movement and insertion in the genome. Overall, this study provides novel insight into the role that the SC plays in genome stability and provides clues as to why SC proteins are among the most rapidly evolving in any organism.

scholarly journals A Rare Case of Aicardi-Goutières Syndrome Who Showed a Positive Evolution after Being Treated with Growth Hormone, High Doses of Melatonin and Neurorehabilitation

2017 ◽  
Author(s):  
Jesús Devesa ◽  
Alba Alonso ◽  
Patricia Porto ◽  
Ana Quintana ◽  
María Carrillo ◽  
...  
Keyword(s):  
De Novo ◽  
Oral Communication ◽  
Blood Analysis ◽  
De Novo Mutation ◽  
Fine Motor ◽  
Unknown Etiology ◽  
Psychomotor Delay ◽  
Developmental Skills ◽  
High Doses ◽  
One Year

1) Background: The Aicardi-Goutières syndrome (AGS) is a rare congenital disease which courses with severe psychomotor delay in neurodevelopment. We studied a 3-years and 4-months old child with very important growth and weight affectation, microcephaly and loss of his developmental skills from 16-months of age, in which previous metabolic and genetic studies discarded any abnormality. Therefore diagnosis was cerebral palsy of unknown etiology. He presented spastic paraparesia, poor fine motricity, cognitive impairment and absence of oral communication. One year after discharge, a de novo mutation was detected in a single nucleotide in the gene IFIH1: c.2317G>C, being then diagnosed of AGS. 2) Methods: Blood analysis showed very low IGF-1 and slightly elevated liver transaminases. Treatment consisted in GH (0.04 mg/kg/day), melatonin (20 mg/day, and after 3-months 50 mg/day), and daily intense neurorehabilitation (5 days/week). Tests for evaluating childhood developmental milestones (GMFM-88, BDIST and the WeeFim test) were carried out every 3-months. 3) Results: The equivalent age at admission (10-months) increased to 24-months at discharge. There were clear improvements in spasticity, fine motor function, swallowing, cognition and autonomy as well as in communication, growth and weight. 4) Conclusion: Most likely melatonin blocked or decreased the interferon signature, allowing GH and neurorehabiltation to act on neurodevelopment.

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