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Copy number variations (CNVs) are important structural variations that can cause significant phenotypic diversity. Reliable CNVs mapping can be achieved by identification of CNVs from different genetic backgrounds. Investigations on the characteristics of overlapping between CNV regions (CNVRs) and protein-coding genes (CNV genes) or miRNAs (CNV-miRNAs) can reveal the potential mechanisms of their regulation. In this study, we used 50 K SNP arrays to detect CNVs in Duroc purebred pig. A total number of 211 CNVRs were detected with a total length of 118.48 Mb, accounting for 5.23% of the autosomal genome sequence. Of these CNVRs, 32 were gains, 175 losses, and four contained both types (loss and gain within the same region). The CNVRs we detected were non-randomly distributed in the swine genome and were significantly enriched in the segmental duplication and gene density region. Additionally, these CNVRs were overlapping with 1,096 protein-coding genes (CNV-genes), and 39 miRNAs (CNV-miRNAs), respectively. The CNV-genes were enriched in terms of dosage-sensitive gene list. The expression of the CNV genes was significantly higher than that of the non-CNV genes in the adult Duroc prostate. Of all detected CNV genes, 22.99% genes were tissue-specific (TSI > 0.9). Strong negative selection had been underway in the CNV-genes as the ones that were located entirely within the loss CNVRs appeared to be evolving rapidly as determined by the median dN plus dS values. Non-CNV genes tended to be miRNA target than CNV-genes. Furthermore, CNV-miRNAs tended to target more genes compared to non-CNV-miRNAs, and a combination of two CNV-miRNAs preferentially synergistically regulated the same target genes. We also focused our efforts on examining CNV genes and CNV-miRNAs functions, which were also involved in the lipid metabolism, including DGAT1, DGAT2, MOGAT2 , miR143, miR335, and miRLET7. Further molecular experiments and independent large studies are needed to confirm our findings. [ABSTRACT FROM AUTHOR]

Background: Congenital heart disease (CHD) is one of the most common birth defects. Copy number variations (CNVs) have been proved to be important genetic factors that contribute to CHD. Here we screened genome-wide CNVs in Chinese children with complete atrioventricular canal (CAVC) and single ventricle (SV), since there were scarce researches dedicated to these two types of CHD. Methods: We screened CNVs in 262 sporadic CAVC cases and 259 sporadic SV cases respectively, using a customized SNP array. The detected CNVs were annotated and filtered using available databases. Results: Among 262 CAVC patients, we identified 6 potentially-causative CNVs in 43 individuals (16.41%, 43/262), including 2 syndrome-related CNVs (7q11.23 and 8q24.3 deletion). Surprisingly, 90.70% CAVC patients with detected CNVs (39/43) were found to carry duplications of 21q11.2–21q22.3, which were recognized as trisomy 21 (Down syndrome, DS). In CAVC with DS patients, the female to male ratio was 1.6:1.0 (24:15), and the rate of pulmonary hypertension (PH) was 41.03% (16/39). Additionally, 6 potentially-causative CNVs were identified in the SV patients (2.32%, 6/259), and none of them was trisomy 21. Most CNVs identified in our cohort were classified as rare (< 1%), occurring just once among CAVC or SV individuals except the 21q11.2–21q22.3 duplication (14.89%) in CAVC cohort. Conclusions: Our study identified 12 potentially-causative CNVs in 262 CAVC and 259 SV patients, representing the largest cohort of these two CHD types in Chinese population. The results provided strong correlation between CAVC and DS, which also showed sex difference and high incidence of PH. The presence of potentially-causative CNVs suggests the etiology of complex CHD is incredibly diverse, and CHD candidate genes remain to be discovered. [ABSTRACT FROM AUTHOR]

A total of 184 Djallonké (West African Dwarf) sheep of Burkina Faso were analysed for Copy Number Variations (CNV) using Ovine 50 K SNP BeadChip genotyping data and two different CNV calling platforms: PennCNV and QuantiSNP. Analyses allowed to identify a total of 63 candidate Copy Number Variations Regions (CNVR) on 11 different ovine chromosomes covering about 82.5 Mb of the sheep genome. Gene‐annotation enrichment analysis allowed to identify a total of 751 potential candidate ovine genes located in the candidate CNVR bounds. Functional annotation allowed to identify five statistically significant Functional Clusters (FC; enrichment factor > 1.3) involving 61 candidate genes. All genes forming significantly enriched FC were located on ovine chromosome (OAR) 21. FC1 (22 genes including PAG4 and PAG6) and FC5 (three genes: CTSC, CTSW and CTSF), coding proteases (peptidases and cathepsins, respectively), were involved in reproductive performance and modulation of gestation. Both FC3 and FC4 were involved in inflammatory and immunologic response through coding serum amyloid A and B‐box‐type zinc finger proteins, respectively. Finally, FC2 consisted of 27 genes (including OR10G6 and OR8B8) involved in olfactory receptor activity, key for animals adapting to new food resources. CNVR identified on at least 15% of individuals were considered CNVR hotspots and further overlapped with previously reported quantitative trait loci (QTL). CNVR hotspots spanning genes putatively involved with lipid metabolism (SKP1, TCF7, JADE2, UBE2B and SAR1B) and differential expression in mammary gland (SEC24A and CDKN2AIPNL) on OAR5 and dairy traits (CCDC198 and SLC35F4) on OAR7 overlapped with QTL associated with lipid metabolism, milk protein yield and milk fat percentage. Information obtained from local sheep populations naturally adapted to harsh environments contributes to increase our understanding of the genomic importance of CNV. [ABSTRACT FROM AUTHOR]

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Autism spectrum disorder (ASD) manifests as a neurodevelopmental condition marked by challenges in social communication, interaction and the performing of repetitive behaviors. The prevalence of autism increases markedly on an annual basis; however, the etiology remains incompletely understood. Cytogenetically visible chromosomal abnormalities, including copy number variations (CNVs), have been shown to contribute to the pathogenesis of ASD. More than 1% of ASD conditions can be explained based on a known genetic locus, whereas CNVs account for 5-10% of cases. However, there are no studies on the Saudi Arabian population for the detection of CNVs linked to ASD, to the best of our knowledge. Therefore, the aim of the present study was to explore the prevalence of CNVs in autistic Saudi Arabian children. Genomic DNA was extracted from the peripheral blood of 14 autistic children along with four healthy control children and then array-based comparative genomic hybridization (aCGH) was used to detect CNVs. Bioinformatics analysis of the aCGH results showed the presence of recurrent and non-recurrent deletion/duplication CNVs in several regions of the genome of autistic children. The most frequent CNVs were 1q21.2, 3p26.3, 4q13.2, 6p25.3, 6q24.2, 7p21.1, 7q34, 7q11.1, 8p23.2, 13q32.3, 14q11.1-q11.2 and 15q11.1-q11.2. In the present study, CNVs in autistic Saudi Arabian children were identified to improve the understanding of the etiology of autism and facilitate its diagnosis. Additionally, the present study identified certain possible pathogenic genes in the CNV region associated with several developmental and neurogenetic diseases. [ABSTRACT FROM AUTHOR]

Copy number variations (CNVs) are middle-sized quantitative genomic variants. They are recognized as an important source of normal variations in the genome as well as a cause of a number of diseases, which has led to a recent surge in interest in their detection in clinical diagnostics. The classical definition of CNVs includes gain or loss of genetic material between 1 kb and 5 Mb. An increase in the resolution of genomic tests during the last decades has been followed by a decrease in the size of altered genomic regions designed as CNV, with the current lower limit of ≥50 bps. A change in dosage of the gene(s) intolerant to haploinsufficiency or exhibit triplosensitivity is obvious and the most common CNV disease-causing mechanism. Alternatively, it could be disruption of a gene or its regulatory elements, a positional effect, or demasking the recessive allele. The phenotype resembles monogenic disease, or it could be part of contiguous gene syndromes, also known as microdeletion and microduplication syndromes (MDDs). Recurrent MDDs, with similar boundaries, originate mostly from non-allelic homologous recombination in hot-spot genomic regions rich in segmental duplications, while non-recurrent MDDs could happen in any part of the genome and be caused by other mechanisms based on DNA repair or errors during DNA replication. Large-scale CNVs, more than 5 Mb in size, could be detected by classical karyotyping. Middle- and low-scale ones require locus-specific techniques like FISH and MLPA, or molecular karyotyping and new-generation sequencing methods for genomic coverage. Array comparative genomic hybridization (a-CGH) is a reliable and gold standard technique for genomic CNV detection in most laboratories today. We aim to present our 5-year laboratory experience in CNV detection and interpretation in postnatal diagnostic settings using the CGH methodology. [ABSTRACT FROM AUTHOR]

Abstract In addition to combating vector‐borne diseases, studying the adaptation of mosquitoes to insecticides provides a remarkable example of evolution‐in‐action driving the selection of complex phenotypes. Actually, most resistant mosquito populations show multi‐resistance phenotypes as a consequence of the variety of insecticides employed and of the complexity of selected resistance mechanisms. Such complexity makes the identification of alleles conferring resistance to specific insecticides challenging and prevents the development of molecular assays to track them in the field. Here we showed that combining simple genetic crosses with pool targeted DNA‐seq can enhance the specificity of resistance allele's detection while maintaining experimental work and sequencing effort at reasonable levels. A multi‐resistant population of the mosquito Aedes aegypti was exposed to three distinct insecticides (deltamethrin, bendiocarb and fenitrothion), and survivors to each insecticide were crossed with a susceptible strain to generate three distinct lines. F2 individuals from each line were then segregated based on their survival to two insecticide doses. Hundreds of genes covering all detoxifying enzymes and insecticide targets together with more than 7,000 intergenic regions equally spread over mosquito genome were sequenced from pools of F0 and F2 individuals unexposed or surviving insecticide. Differential coverage analysis identified 39 detoxification enzymes showing an increased gene copy number in association with resistance. Combining an allele frequency filtering approach with a Bayesian FST‐based genome scan identified multiple genomic regions showing strong selection signatures together with 50 nonsynonymous variations associated with resistance. This study provides a simple and cost‐effective approach to improve the specificity of resistance allele's detection in multi‐resistant populations while reducing false positives frequently arising when comparing populations showing divergent genetic backgrounds. The identification of novel DNA resistance markers opens new opportunities for improving the tracking of insecticide resistance in the field.

Abstract Background Copy Number Variations (CNVs) are gain or loss of DNA segments that are known to play a role in shaping a wide range of phenotypes. In this study, we used two dairy cattle populations, Holstein Friesian and Jersey, to discover CNVs using the Illumina BovineHD Genotyping BeadChip aligned to the ARS-UCD1.2 assembly. The discovered CNVs were investigated for their functional impact and their population genetics features. Results We discovered 14,272 autosomal CNVs, which were aggregated into 1755 CNV regions (CNVR) from 451 animals. These CNVRs together cover 2.8% of the bovine autosomes. The assessment of the functional impact of CNVRs showed that rare CNVRs (MAF

Abstract Background Variome may be used for designating complex system of interplay between genomic variations specific for an individual or a disease. Despite the recognized complexity of genomic basis for phenotypic traits and diseases, studies of genetic causes of a disease are usually dedicated to the identification of single causative genomic changes (mutations). When such an artificially simplified model is employed, genomic basis of phenotypic outcomes remains elusive in the overwhelming majority of human diseases. Moreover, it is repeatedly demonstrated that multiple genomic changes within an individual genome are likely to underlie the phenome. Probably the best example of cumulative effect of variome on the phenotype is CNV (copy number variation) burden. Accordingly, we have proposed a variome concept based on CNV studies providing the evidence for the existence of a CNVariome (the set of CNV affecting an individual genome), a target for genomic analyses useful for unraveling genetic mechanisms of diseases and phenotypic traits. Conclusion Variome (CNVariome) concept suggests that a genomic milieu is determined by the whole set of genomic variations (CNV) within an individual genome. The genomic milieu is likely to result from interplay between these variations. Furthermore, such kind of variome may be either individual or disease-specific. Additionally, such variome may be pathway-specific. The latter is able to affect molecular/cellular pathways of genome stability maintenance leading to occurrence of genomic/chromosome instability and/or somatic mosaicism resulting in somatic variome. This variome type seems to be important for unraveling disease mechanisms, as well. Finally, it appears that bioinformatic analysis of both individual and somatic variomes in the context of diseases- and pathway-specific variomes is the most promising way to determine genomic basis of the phenome and to unravel disease mechanisms for the management and treatment of currently incurable diseases.

Abstract Background Hirschsprung Disease (HSCR) is a congenital defect of the intestinal innervations characterized by complex inheritance. Many susceptibility genes including RET, the major HSCR gene, and several linked regions and associated loci have been shown to contribute to disease pathogenesis. Nonetheless, a proportion of patients still remains unexplained. Copy Number Variations (CNVs) have already been involved in HSCR, and for this reason we performed Comparative Genomic Hybridization (CGH), using a custom array with high density probes. Results A total of 20 HSCR candidate regions/genes was tested in 55 sporadic patients and four patients with already known chromosomal aberrations. Among 83 calls, 12 variants were experimentally validated, three of which involving the HSCR crucial genes SEMA3A/3D, NRG1, and PHOX2B. Conversely RET involvement in HSCR does not seem to rely on the presence of CNVs while, interestingly, several gains and losses did co-occur with another RET defect, thus confirming that more than one predisposing event is necessary for HSCR to develop. New loci were also shown to be involved, such as ALDH1A2, already found to play a major role in the enteric nervous system. Finally, all the inherited CNVs were of maternal origin. Conclusions Our results confirm a wide genetic heterogeneity in HSCR occurrence and support a role of candidate genes in expression regulation and cell signaling, thus contributing to depict further the molecular complexity of the genomic regions involved in the Enteric Nervous System development. The observed maternal transmission bias for HSCR associated CNVs supports the hypothesis that in females these variants might be more tolerated, requiring additional alterations to develop HSCR disease.

Abstract Background Structural variations such as copy number variations (CNVs) have a functional impact on various human traits. This study profiled genome-wide CNVs in Korean patients with rheumatoid arthritis (RA) to investigate the efficacy of treatment with TNF-α blockers. Methods A total of 357 Korean patients with RA were examined for the efficacy of TNF-α blocker treatment. Disease activity indexes were measured at baseline and 6 months after the treatment. The patients were classified as responders and non-responders based on the change in disease activity indexes according to the EULAR response criteria. CNVs in the same patients were profiled using fluorescence signal intensity data generated by a genome-wide SNP array. The association of CNVs with response to TNF-α blockers was analyzed by multivariate logistic regression accounting for genetic background and clinical factors including body mass index, gender, baseline disease activity, TNF-α blocker used, and methotrexate treatment. Results The study subjects varied in their responses to TNF-α blockers and had 286 common CNVs in autosomes. We identified that the 3.8-kb deletion at 2q14.3 in 5% of the subjects was associated with response to TNF-α blockers (1.37 × 10− 5 ≤ P ≤ 4.07 × 10− 4) at a false discovery rate threshold of 5%. The deletion in the identified CNV was significantly more frequent in the non-responders than in the responders, indicating worse response to TNF-α blockers in the deletion carriers. The 3.8-kb deletion at 2q14.3 is located in an intergenic region with the binding sites of two transcription factors, MAFF and MAFK. Conclusions This study obtained the CNV landscape of Korean patients with RA and identified the common regional deletion associated with poor response to treatment with TNF-α blockers.

DNA methylation in CpGs dinucleotides is associated with high mutability and disappearance of CpG sites during evolution. Although the high mutability of CpGs is thought to be relevant for vertebrate evolution, very little is known on the role of CpG-related mutations in the genomic diversification of vertebrates. Our study analysed genetic differences in chickens, between Red Junglefowl (RJF; the living closest relative to the ancestor of domesticated chickens) and domesticated breeds, to identify genomic dynamics that have occurred during the process of their domestication, focusing particularly on CpG-related mutations. Single nucleotide polymorphisms (SNPs) and copy number variations (CNVs) between RJF and these domesticated breeds were assessed in a reduced fraction of their genome. Additionally, DNA methylation in the same fraction of the genome was measured in the sperm of RJF individuals to identify possible correlations with the mutations found between RJF and the domesticated breeds. Our study shows that although the vast majority of CpG-related mutations found relate to CNVs, CpGs disproportionally associate to SNPs in comparison to CNVs, where they are indeed substantially under-represented. Moreover, CpGs seem to be hotspots of mutations related to speciation. We suggest that, on the one hand, CpG-related mutations in CNV regions would promote genomic ‘flexibility’ in evolution, i.e., the ability of the genome to expand its functional possibilities; on the other hand, CpG-related mutations in SNPs would relate to genomic ‘specificity’ in evolution, thus, representing mutations that would associate with phenotypic traits relevant for speciation.

Abstract Background The etiology of TOF is complex and the genesis of TOF has been associated with environmental factors and genetic disorders, including chromosomal anomalies, aneuploidies, 22q11.2 deletion and single-gene disease. Previous literatures have shown that a chromosome alteration in about 30% patients with TOF and recently published articles reported that 22q11.2 deletion syndrome accounts for 16% cases with TOF diagnosed postnatally. CMA now is considered as gold standard for detecting genetic anomalies in fetuses with congenital malformations. CMA could detect a 6.6–25% incremental yield of CNVs in CHDs. The aim of this study was to assess the genetic anomalies in fetal tetralogy of Fallot (TOF) by using high-definition CMA. Methods This retrospective study reviewed all the fetuses diagnosed with TOF between 2013 and 2018. Prenatal ultrasongraphic findings, including cardiac angle, and the findings of CMA using Affymetrix CytoScan HD array were collected. Results Ninety-six fetuses with TOF and known genetic results were enrolled. Right aortic arch was the most common associated anomalies (22.9%). One fetus with trisomy 18, one with 46, XX, t (7;10)(q36;q22), one with 47, XYY and five with trisomy 21 were identified. Clinically significant CNVs occurred in 6.8% and uncertain significant CNVs in 3.4% fetal TOF with normal karyotype. A total of four cases with 22q11.2 microdeletion and two fetuses with Yq11.223q11.23 microduplication have been identified. Genetic anomalies, including chromosomal aberrations and pathogenic CNVs, were significantly higher in the TOF with extracardiac anomaly group than in the TOF without extracardiac anomaly group (P = 0.005). Abnormal cardiac angle was noticed in 24.0% fetal TOF. Genetic anomalies were more common in the TOF with abnormal cardiac angle than with normal cardiac angle (P = 0.001). On the other hand, abnormal cardiac angle was noticed in 64.3% fetal TOF with genetic anomalies while abnormal cardiac angle occurred in 17.1% fetal TOF with normal genetic results (P = 0.001). Conclusions Genetic testing should be offered, specially using microarray analysis, for the fetal TOF with abnormal cardiac angle or extracardiac defects.

Abstract Background Melanoma is an aggressive type of skin cancer whose aetiology remains elusive as both environmental and genetic factors can contribute to its development. Recent studies have demonstrated the existence of multiple copies of E2F1 gene in melanoma specimens which could explain the deregulated E2F1 activity in this type of cancer. This finding suggests a key role for this transcription factor in the malignant transformation of melanocytes. Therefore, E2F1 has been considered as a potential therapeutic target for this form of skin cancer. Since germline copy number variations (CNVs) have been associated with increased susceptibility to different types of cancer, the aim of our study was to assess germline E2F1 CNV in melanoma patients. However, CNVs not necessarily lead to gene dosage imbalance, hence, further factors, in association with CNVs, could contribute to clinical manifestations. Considering that heat stress has been hypothesised as a contributing factor to skin cancer, we also investigated the effect of heat stress on E2F1 expression. Methods E2F1 CNV was measured in genomic DNA isolated from blood of 552 patients diagnosed with melanoma and 520 healthy subjects using TaqMan Copy Number Assays. E2F1 mRNA expression was also evaluated by RT-qPCR in the melanoma cell line, SK MEL 267, before and after exposure to heat stress. Results We found that patients diagnosed with melanoma (1.6%, 9/552) harboured frequently altered germline E2F1 copies compared to healthy subjects (0%, 0/520). Moreover, the difference among the two groups was statistically significant (p = 0.004). Furthermore, we found that heat exposure alone can significantly induce E2F1 expression. Conclusions This is the first study that shows a relation between germline E2F1 CNV and melanoma, suggesting that altered copies of this gene might be a predisposing factor to skin cancer. Our results also suggest that environmental insults, such as heat stress, could contribute to an aberrant E2F1 activity by inducing E2F1 mRNA expression. Therefore, subjects with multiple constitutive copies of E2F1 are at greater risk of developing melanoma when exposed to heat. Altogether our results corroborate with the hypothesis that susceptibility to melanoma depends on both the environment and genetic factors.

Objectives: Despite a reduction in the incidence and mortality rates of gastric cancer (GC), it remains the fifth most frequently diagnosed malignancy globally. A better understanding of the regulatory mechanisms involved in the progression and development of GC is important for developing novel targeted approaches for treatment. We aimed to identify a set of differentially regulated pathways and cellular, molecular, and physiological system development and functions in GC patients infected with H. pylori infection based on copy number variation (CNV) data using next-generation knowledge discovery (NGKD) methods. Methods: In this study, we used our previous CNV data derived from tissue samples from GC patients (n = 33) and normal gastric samples (n = 15) by the comparative genome hybridization (CGH) method using Illumina HumanOmni1-Quad v.1.0 BeadChip (Zenodo Accession No: 1346283). The variant effects analysis of genetic gain or loss of function in GC was conducted using Ingenuity Pathway Analysis (IPA) software. In addition, in silico validation was performed with iPathwayGuide software using high-throughput RNA sequencing (RNAseq) data (GSE83088) from GC patients. Results: We observed 213 unique CNVs in the control group, 420 unique CNVs in the GC group, and 225 common variants. We found that cancer, gastrointestinal diseases, and organismal injury and abnormalities were the three diseases or disorders that were most affected in the GC group. We also identified that the programmed cell death ligand 1 (PD-L1) cancer immunotherapy pathway, T-cell apoptosis, T-cell exhaustion, and Type 1 regulatory T-cell (Tr1 cells) specialization were dysregulated in GC patients. RNAseq data from GC patients showed that the PD-1/PD-L1 pathway was significantly upregulated in GC samples compared with controls. Conclusions: In conclusion, in the present study, we decoded differentially impacted GC-specific diseases and biological functions and pathways based on CNV data using NGKD methods that can be adopted to design personalized therapeutic approaches for patients with GC in a typical clinical milieu.

Copy number variation (CNV), is defined as repetitions or deletions of genomic segments of 1 Kb to 5 Mb, and is a major trigger for human disease. The high-throughput and low-cost characteristics of next-generation sequencing technology provide the possibility of the detection of CNVs in the whole genome, and also greatly improve the clinical practicability of next-generation sequencing (NGS) testing. However, current methods for the detection of CNVs are easily affected by sequencing and mapping errors, and uneven distribution of reads. In this paper, we propose an improved approach, CNV-MEANN, for the detection of CNVs, involving changing the structure of the neural network used in the MFCNV method. This method has three differences relative to the MFCNV method: (1) it utilizes a new feature, mapping quality, to replace two features in MFCNV, (2) it considers the influence of the loss categories of CNV on disease prediction, and refines the output structure, and (3) it uses a mind evolutionary algorithm to optimize the backpropagation (neural network) neural network model, and calculates individual scores for each genome bin to predict CNVs. Using both simulated and real datasets, we tested the performance of CNV-MEANN and compared its performance with those of seven widely used CNV detection methods. Experimental results demonstrated that the CNV-MEANN approach outperformed other methods with respect to sensitivity, precision, and F1-score. The proposed method was able to detect many CNVs that other approaches could not, and it reduced the boundary bias. CNV-MEANN is expected to be an effective method for the analysis of changes in CNVs in the genome.

BackgroundSubmicroscopic segmental imbalances detected by array-comparative genomic hybridization (array-CGH) were discovered to be common in chronic myeloid leukemia (CML) patients with t(9;22) as the sole chromosomal anomaly. To confirm the findings of the previous study and expand the investigation, additional CML patients with t(9;22) as the sole chromosomal anomaly were recruited and copy number variants (CNVs) were searched for.MethodsKaryotyping tests were performed on 106 CML patients during January 2010–September 2019 in our Genetics Laboratory. Eighty-four (79.2%) patients had the Philadelphia (Ph) chromosome as the sole chromosomal anomaly. Only 49(58.3%) of these 84 patients had sufficient marrow or leukemia blood materials to additionally be included in the array-CGH analysis. Fluorescence in situ hybridization (FISH) was carried out to confirm the genes covered by the deleted or duplicated regions of the CNVs.Results11(22.4%) out of the 49 patients were found to have one to three somatic segmental somatic segmental (CNVs), including fourteen deletions and three duplications. The common region associated with deletions was on 9q33.3-34.12. Identified in five (45.5%) of the 11 positive patients with segmental CNVs, the deletions ranged from 106 kb to 4.1 Mb in size. Two (18.2%) cases had a deletion in the ABL1-BCR fusion gene on der (9), while three (27.3%) cases had a deletion in the ASS1 gene. The remaining CNVs were randomly distributed on different autosomes.ConclusionSubtle genomic CNVs are relatively common in CML patients without cytogenetically visible additional chromosomal aberrations (ACAs). Long-term studies investigating the potential impact on patient prognosis and treatment outcome is underway.

PurposeThe aim of this study was to probe the global profile of the EYS-associated genotype-phenotype trait in the worldwide reported IRD cases and to build a model for predicting disease progression as a reference for clinical consultation.MethodsThis retrospective study of 420 well-documented IRD cases with mutations in the EYS gene included 39 patients from a genotype-phenotype study of inherited retinal dystrophy (IRD) conducted at the Beijing Institute of Ophthalmology and 381 cases retrieved from global reports. All patients underwent ophthalmic evaluation. Mutations were revealed using next-generation sequencing, followed by Sanger DNA sequencing and real-time quantitative PCR analysis. Multiple regression models and statistical analysis were used to assess the genotype and phenotype characteristics and traits in this large cohort.ResultsA total of 420 well-defined patients with 841 identified mutations in the EYS gene were successfully obtained. The most common pathogenic variant was a frameshift c.4957dupA (p.S1653Kfs∗2) in exon 26, with an allele frequency of 12.7% (107/841), followed by c.8805C > A (p.Y2935X) in exon 43, with an allele frequency of 5.9% (50/841). Two new hot spots were identified in the Chinese cohort, c.1750G > T (p.E584X) and c.7492G > C (p.A2498P). Several EYS mutation types were identified, with CNV being relatively common. The mean age of onset was 20.54 ± 11.33 (4–46) years. Clinical examinations revealed a typical progression of RPE atrophy from the peripheral area to the macula.ConclusionThis large global cohort of 420 IRD cases, with 262 distinct variants, identified genotype-phenotype correlations and mutation spectra with hotspots in the EYS gene.

Copy number variation (CNV) is a genomic mutation that plays an important role in tumor evolution and tumor genesis. Accurate detection of CNVs from next-generation sequencing (NGS) data is still a challenging task due to artifacts such as uneven mapped reads and unbalanced amplitudes of gains and losses. This study proposes a new approach called HBOS-CNV to detect CNVs from NGS data. The central point of HBOS-CNV is that it uses a new statistic, the histogram-based outlier score (HBOS), to evaluate the fluctuation of genome bins to determine those of changed copy numbers. In comparison with existing statistics in the evaluation of CNVs, HBOS is a non-linearly transformed value from the observed read depth (RD) value of each genome bin, having the potential ability to relieve the effects resulted from the above artifacts. In the calculation of HBOS values, a dynamic width histogram is utilized to depict the density of bins on the genome being analyzed, which can reduce the effects of noises partially contributed by mapping and sequencing errors. The evaluation of genome bins using such a new statistic can lead to less extremely significant CNVs having a high probability of detection. We evaluated this method using a large number of simulation datasets and compared it with four existing methods (CNVnator, CNV-IFTV, CNV-LOF, and iCopyDav). The results demonstrated that our proposed method outperforms the others in terms of sensitivity, precision, and F1-measure. Furthermore, we applied the proposed method to a set of real sequencing samples from the 1000 Genomes Project and determined a number of CNVs with biological meanings. Thus, the proposed method can be regarded as a routine approach in the field of genome mutation analysis for cancer samples.

Copy number variation (CNV), is defined as repetitions or deletions of genomic segments of 1 Kb to 5 Mb, and is a major trigger for human disease. The high-throughput and low-cost characteristics of next-generation sequencing technology provide the possibility of the detection of CNVs in the whole genome, and also greatly improve the clinical practicability of next-generation sequencing (NGS) testing. However, current methods for the detection of CNVs are easily affected by sequencing and mapping errors, and uneven distribution of reads. In this paper, we propose an improved approach, CNV-MEANN, for the detection of CNVs, involving changing the structure of the neural network used in the MFCNV method. This method has three differences relative to the MFCNV method: (1) it utilizes a new feature, mapping quality, to replace two features in MFCNV, (2) it considers the influence of the loss categories of CNV on disease prediction, and refines the output structure, and (3) it uses a mind evolutionary algorithm to optimize the backpropagation (neural network) neural network model, and calculates individual scores for each genome bin to predict CNVs. Using both simulated and real datasets, we tested the performance of CNV-MEANN and compared its performance with those of seven widely used CNV detection methods. Experimental results demonstrated that the CNV-MEANN approach outperformed other methods with respect to sensitivity, precision, and F1-score. The proposed method was able to detect many CNVs that other approaches could not, and it reduced the boundary bias. CNV-MEANN is expected to be an effective method for the analysis of changes in CNVs in the genome. [ABSTRACT FROM AUTHOR]

Objectives: To explore the copy number variations (CNVs) of fetal congenital cystic adenomatoid malformation (CCAM). Methods: Fetuses with CCAM were investigated by karyotypes and chromosomal microarray analysis (CMA). The cases were classified as isolated or CCAM with additional structural anomalies. The pregnancy outcome and neonatal prognosis were reported after the follow-up investigation. Results: The karyotypes of 43 fetuses were analyzed and no abnormal karyotype was detected. Thirty-seven cases were further tested using CMA. The CMA identified pathogenic CNVs in three fetuses with a pathogenic detection rate of 8.1%. Well-known microdeletion or microduplication syndromes, including RCAD syndrome, HNPP, and CMT1A were identified, among which HNPP and CMT1A were incidental findings. After excluding two incidental findings, there were no pathogenic CNVs in isolated CCAM. There were no significant differences in pathogenic CNVs between isolated CCAM and CCAM with additional structural anomalies (0%, 0/31 versus 16.7%, 1/6, p=.162). Nearly half of the patients (53.8%, 14/26) underwent surgery after birth with good postoperative recoveries while the remaining half patients were spontaneous regression or asymptomatic. Conclusions: The results demonstrated the value of CMA in the prenatal diagnosis of CCAM. CCAM associated with other structural defects enhanced the frequency of pathogenic CNVs while isolated CCAM may not be associated with an increase in the prevalence of pathogenic CNVs. CCAMs have an overall good prognosis. [ABSTRACT FROM AUTHOR]

Background: Submicroscopic segmental imbalances detected by array-comparative genomic hybridization (array-CGH) were discovered to be common in chronic myeloid leukemia (CML) patients with t (9;22) as the sole chromosomal anomaly. To confirm the findings of the previous study and expand the investigation, additional CML patients with t (9;22) as the sole chromosomal anomaly were recruited and copy number variants (CNVs) were searched for. Methods: Karyotyping tests were performed on 106 CML patients during January 2010–September 2019 in our Genetics Laboratory. Eighty-four (79.2%) patients had the Philadelphia (Ph) chromosome as the sole chromosomal anomaly. Only 49(58.3%) of these 84 patients had sufficient marrow or leukemia blood materials to additionally be included in the array-CGH analysis. Fluorescence in situ hybridization (FISH) was carried out to confirm the genes covered by the deleted or duplicated regions of the CNVs. Results: 11(22.4%) out of the 49 patients were found to have one to three somatic segmental somatic segmental (CNVs), including fourteen deletions and three duplications. The common region associated with deletions was on 9q33.3-34.12. Identified in five (45.5%) of the 11 positive patients with segmental CNVs, the deletions ranged from 106 kb to 4.1 Mb in size. Two (18.2%) cases had a deletion in the ABL1-BCR fusion gene on der (9), while three (27.3%) cases had a deletion in the ASS1 gene. The remaining CNVs were randomly distributed on different autosomes. Conclusion: Subtle genomic CNVs are relatively common in CML patients without cytogenetically visible additional chromosomal aberrations (ACAs). Long-term studies investigating the potential impact on patient prognosis and treatment outcome is underway. [ABSTRACT FROM AUTHOR]

Background: Since 2011, screening maternal blood for cell-free foetal DNA (cffDNA) fragments has offered a robust clinical tool to classify pregnancy as low or high-risk for Down, Edwards, and Patau syndromes. With recent advances in molecular biology and improvements in data analysis algorithms, the screening's scope of analysis continues to expand. Indeed, screening now encompassess additional conditions, including aneuploidies for sex chromosomes, microdeletions and microduplications, rare autosomal trisomies, and, more recently, segmental deletions and duplications called copy number variations (CNVs). Yet, the ability to detect CNVs creates a new challenge for cffDNA analysis in couples in which one member carries a structural rearrangement such as a translocation or inversion. Case presentation: We report a segmental duplication of the long arm of chromosome 3 and a segmental deletion of the short arm of chromosome 5 detected by cffDNA analysis in a 25-year-old pregnant woman. The blood sample was sequenced on a NextSeq 550 (Illumina) using the VeriSeq NIPT Solution v1 assay. G-band karyotyping in amniotic fluid only detected an abnormality in chromosome 5. Next-generation sequencing in amniocytes confirmed both abnormalities and identified breakpoints in 3q26.32q29 and 5p13.3p15. The foetus died at 21 weeks of gestation due to multiple abnormalities, and later G-band karyotyping in the parents revealed that the father was a carrier of a balanced reciprocal translocation [46,XY,t(3;5)(q26.2;p13)]. Maternal karyotype appeared normal. Conclusion: This case provides evidence that extended cffDNA can detect, in addition to aneuploidies for whole chromosomes, large segmental aneuploidies. In some cases, this may indicate the presence of chromosomal rearrangements in a parent. Such abnormalities are outside the scope of standard cffDNA analysis targeting chromosomes 13, 18, 21, X, and Y, potentially leading to undiagnosed congenital conditions. [ABSTRACT FROM AUTHOR]

Copy number variation (CNV) is a genomic mutation that plays an important role in tumor evolution and tumor genesis. Accurate detection of CNVs from next-generation sequencing (NGS) data is still a challenging task due to artifacts such as uneven mapped reads and unbalanced amplitudes of gains and losses. This study proposes a new approach called HBOS-CNV to detect CNVs from NGS data. The central point of HBOS-CNV is that it uses a new statistic, the histogram-based outlier score (HBOS), to evaluate the fluctuation of genome bins to determine those of changed copy numbers. In comparison with existing statistics in the evaluation of CNVs, HBOS is a non-linearly transformed value from the observed read depth (RD) value of each genome bin, having the potential ability to relieve the effects resulted from the above artifacts. In the calculation of HBOS values, a dynamic width histogram is utilized to depict the density of bins on the genome being analyzed, which can reduce the effects of noises partially contributed by mapping and sequencing errors. The evaluation of genome bins using such a new statistic can lead to less extremely significant CNVs having a high probability of detection. We evaluated this method using a large number of simulation datasets and compared it with four existing methods (CNVnator, CNV-IFTV, CNV-LOF, and iCopyDav). The results demonstrated that our proposed method outperforms the others in terms of sensitivity, precision, and F1-measure. Furthermore, we applied the proposed method to a set of real sequencing samples from the 1000 Genomes Project and determined a number of CNVs with biological meanings. Thus, the proposed method can be regarded as a routine approach in the field of genome mutation analysis for cancer samples. [ABSTRACT FROM AUTHOR]

Background: To investigate the genetic contribution of copy number variations (CNVs) in Wingless-type MMTV integration site family, member 4 (WNT4), in a Chinese population with Müllerian anomalies (MA), copy number analysis of WNT4 by Multiplex ligation-dependent probe amplification (MLPA) was performed on 248 female patients. Some studies have shown that heterozygous missense mutation of WNT4 can lead to MA. However, few studies on the relationship between WNT4 CNVs and MA have been performed.Results: Among the 248 Chinese women affected by MA in this study, heterozygous deletion of WNT4 was detected in a single patient.Conclusions: MLPA identified one heterozygous deletion in WNT4 in a single female patient among 248 Chinese women affected by MA. This study firstly reports CNVs of WNT4 in a large sample of MA patients from the Chinese population, which suggests that CNVs of WNT4 cannot be excluded in the occurrence of MA. This provides a genetic basis for precise treatment in the future. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is available in the text. Objective: Although autism spectrum disorder (ASD) occurs worldwide, most genomic studies on ASD were performed on those of Western ancestry. We hypothesized ASD-related copy number variations (CNVs) of Japanese individuals might be different from those of Western individuals. Methods: Subjects were recruited from the Hirosaki 5-year-old children's developmental health check-up (HFC) between 2013 and 2016 (ASD group; n = 68, control group; n = 124). This study conducted CNV analysis using genomic DNA from peripheral blood of 5-year-old Japanese children. Fisher's exact test was applied for profiling subjects and CNV loci. Results: Four ASD-related CNVs: deletion at 12p11.1, duplications at 4q13.2, 8p23.1 and 18q12.3 were detected (P = 0.015, 0.024, 0.009, 0.004, respectively). Specifically, the odds ratio of duplication at 18q12.3 was highest among the 4 CNVs (odds ratio, 8.13). Conclusions: Four CNVs: microdeletion at 12p11.1, microduplications at 4q13.2, 8p23.1 and 18q12.3 were detected as ASD-related CNVs in Japanese children in this study. Although these CNVs were consistent with several reports by Western countries at cytoband levels, these did not consistent at detailed genomic positions and sizes. Our data indicate the possibility that these CNVs are characteristic of Japanese children with ASD. We conclude that Japanese individuals with ASD may harbor CNVs different from those of Western individuals with ASD. [ABSTRACT FROM AUTHOR]

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.

Purpose: Exon deletions make up to 80% of mutations in the DMD gene, which cause Duchenne and Becker muscular dystrophy. Exon 45-55 regions were reported as deletion hotspots and intron 44 harbored more than 25% of deletion start points. We aimed to investigate the fine structures of breakpoints in intron 44 to find potential mechanisms of large deletions in intron 44.Methods: Twenty-two dystrophinopathy patients whose deletion started in intron 44 were sequenced using long-read sequencing of a DMD gene capture panel. Sequence homology, palindromic sequences, and polypyrimidine sequences were searched at the breakpoint junctions. RepeatMasker was used to analyze repetitive elements and Mfold was applied to predict secondary DNA structure.Results: With a designed DMD capture panel, 22 samples achieved 2.25 gigabases and 1.28 million reads on average. Average depth was 308× and 99.98% bases were covered at least 1×. The deletion breakpoints in intron 44 were scattered and no breakpoints clustered in any region less than 500 bp. A total of 72.7% of breakpoints located in distal 100 kb of intron 44 and more repetitive elements were found in this region. Microhomologies of 0–1 bp were found in 36.4% (8/22) of patients, which corresponded with non-homologous end-joining. Microhomologies of 2–20 bp were found in 59.1% (13/22) of patients, which corresponded with microhomology-mediated end-joining. Moreover, a 7 bp insertion was found in one patient, which might be evidence of aberrant replication origin firing. Palindromic sequences, polypyrimidine sequences, and small hairpin loops were found near several breakpoint junctions. No evidence of large hairpin loop formation in deletion root sequences was observed.Conclusion: This study was the first to explore possible mechanisms underlying exon deletions starting from intron 44 of the DMD gene based on long-read sequencing. Diverse mechanisms might be associated with deletions in the DMD gene.

Congenital heart defects (CHD) are the most common developmental abnormalities, affecting approximately 0.9% of livebirths. Genetic factors, including copy number variations (CNVs), play an important role in their development. The most common CNVs are found on chromosome 22q11.2. The genomic instability of this region, caused by the eight low copy repeats (LCR A-H), may result in several recurrent and/or rare microdeletions and duplications, including the most common, ∼3 Mb large LCR A-D deletion (classical 22q.11.2 deletion syndrome). We aimed to screen 22q11.2 CNVs in a large Hungarian pediatric and adult CHD cohort, regardless of the type of their CHDs. All the enrolled participants were cardiologically diagnosed with non-syndromic CHDs. A combination of multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis and droplet digital PCR methods were used to comprehensively assess the detected 22q11.2 CNVs in 212 CHD-patients. Additionally, capillary sequencing was performed to detect variants in the TBX1 gene, a cardinal gene located in 22q11.2. Pathogenic CNVs were detected in 5.2% (11/212), VUS in 0.9% and benign CNVs in 1.8% of the overall CHD cohort. In patients with tetralogy of Fallot the rate of pathogenic CNVs was 17% (5/30). Fifty-four percent of all CNVs were typical proximal deletions (LCR A-D). However, nested (LCR A-B) and central deletions (LCR C-D), proximal (LCR A-D) and distal duplications (LCR D-E, LCR D-H, LCR E-H, LCR F-H) and rare combinations of deletions and duplications were also identified. Segregation analysis detected familial occurrence in 18% (2/11) of the pathogenic variants. Based on in-depth clinical information, a detailed phenotype–genotype comparison was performed. No pathogenic variant was identified in the TBX1 gene. Our findings confirmed the previously described large phenotypic diversity in the 22q11.2 CNVs. MLPA proved to be a highly efficient genetic screening method for our CHD-cohort. Our results highlight the necessity for large-scale genetic screening of CHD-patients and the importance of early genetic diagnosis in their clinical management.

Abstract Background Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early‐onset non‐progressive involuntary movements. Although NKX2‐1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2‐1 gene, indicating that mutations of non‐coding regulatory elements of NKX2‐1 may also play a role. Methods and Results By using whole‐genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2‐1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2‐1 on chromosome 14q13.2‐q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non‐coding sequences. Conclusion We propose that the deletion of potential regulatory elements necessary for NKX2‐1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease‐causing mechanism for BHC.

We investigated the genome-wide distribution of CNVs in the Alzheimer's disease (AD) Neuroimaging Initiative (ADNI) sample (146 with AD, 313 with Mild Cognitive Impairment (MCI), and 181 controls). Comparison of single CNVs between cases (MCI and AD) and controls shows overrepresentation of large heterozygous deletions in cases (p-value

Background: Copy number variations (CNV) are a significant source of variation in the genome and are therefore essential to the understanding of genetic characterization. The aim of this study was to develop a fine-scaled copy number variation map for African goats. We used sequence data from multiple breeds and from multiple African countries. Results: A total of 253,553 CNV (244,876 deletions and 8677 duplications) were identified, corresponding to an overall average of 1393 CNV per animal. The mean CNV length was 3.3 kb, with a median of 1.3 kb. There was substantial differentiation between the populations for some CNV, suggestive of the effect of population-specific selective pressures. A total of 6231 global CNV regions (CNVR) were found across all animals, representing 59.2 Mb (2.4%) of the goat genome. About 1.6% of the CNVR were present in all 34 breeds and 28.7% were present in all 5 geographical areas across Africa, where animals had been sampled. The CNVR had genes that were highly enriched in important biological functions, molecular functions, and cellular components including retrograde endocannabinoid signaling, glutamatergic synapse and circadian entrainment. Conclusions: This study presents the first fine CNV map of African goat based on WGS data and adds to the growing body of knowledge on the genetic characterization of goats. [ABSTRACT FROM AUTHOR]

Purpose: Exon deletions make up to 80% of mutations in the DMD gene, which cause Duchenne and Becker muscular dystrophy. Exon 45-55 regions were reported as deletion hotspots and intron 44 harbored more than 25% of deletion start points. We aimed to investigate the fine structures of breakpoints in intron 44 to find potential mechanisms of large deletions in intron 44. Methods: Twenty-two dystrophinopathy patients whose deletion started in intron 44 were sequenced using long-read sequencing of a DMD gene capture panel. Sequence homology, palindromic sequences, and polypyrimidine sequences were searched at the breakpoint junctions. RepeatMasker was used to analyze repetitive elements and Mfold was applied to predict secondary DNA structure. Results: With a designed DMD capture panel, 22 samples achieved 2.25 gigabases and 1.28 million reads on average. Average depth was 308× and 99.98% bases were covered at least 1×. The deletion breakpoints in intron 44 were scattered and no breakpoints clustered in any region less than 500 bp. A total of 72.7% of breakpoints located in distal 100 kb of intron 44 and more repetitive elements were found in this region. Microhomologies of 0–1 bp were found in 36.4% (8/22) of patients, which corresponded with non-homologous end-joining. Microhomologies of 2–20 bp were found in 59.1% (13/22) of patients, which corresponded with microhomology-mediated end-joining. Moreover, a 7 bp insertion was found in one patient, which might be evidence of aberrant replication origin firing. Palindromic sequences, polypyrimidine sequences, and small hairpin loops were found near several breakpoint junctions. No evidence of large hairpin loop formation in deletion root sequences was observed. Conclusion: This study was the first to explore possible mechanisms underlying exon deletions starting from intron 44 of the DMD gene based on long-read sequencing. Diverse mechanisms might be associated with deletions in the DMD gene. [ABSTRACT FROM AUTHOR]

Congenital heart defects (CHD) are the most common developmental abnormalities, affecting approximately 0.9% of livebirths. Genetic factors, including copy number variations (CNVs), play an important role in their development. The most common CNVs are found on chromosome 22q11.2. The genomic instability of this region, caused by the eight low copy repeats (LCR A-H), may result in several recurrent and/or rare microdeletions and duplications, including the most common, ∼3 Mb large LCR A-D deletion (classical 22q.11.2 deletion syndrome). We aimed to screen 22q11.2 CNVs in a large Hungarian pediatric and adult CHD cohort, regardless of the type of their CHDs. All the enrolled participants were cardiologically diagnosed with non-syndromic CHDs. A combination of multiplex ligation-dependent probe amplification (MLPA), chromosomal microarray analysis and droplet digital PCR methods were used to comprehensively assess the detected 22q11.2 CNVs in 212 CHD-patients. Additionally, capillary sequencing was performed to detect variants in the TBX1 gene, a cardinal gene located in 22q11.2. Pathogenic CNVs were detected in 5.2% (11/212), VUS in 0.9% and benign CNVs in 1.8% of the overall CHD cohort. In patients with tetralogy of Fallot the rate of pathogenic CNVs was 17% (5/30). Fifty-four percent of all CNVs were typical proximal deletions (LCR A-D). However, nested (LCR A-B) and central deletions (LCR C-D), proximal (LCR A-D) and distal duplications (LCR D-E, LCR D-H, LCR E-H, LCR F-H) and rare combinations of deletions and duplications were also identified. Segregation analysis detected familial occurrence in 18% (2/11) of the pathogenic variants. Based on in-depth clinical information, a detailed phenotype–genotype comparison was performed. No pathogenic variant was identified in the TBX1 gene. Our findings confirmed the previously described large phenotypic diversity in the 22q11.2 CNVs. MLPA proved to be a highly efficient genetic screening method for our CHD-cohort. Our results highlight the necessity for large-scale genetic screening of CHD-patients and the importance of early genetic diagnosis in their clinical management. [ABSTRACT FROM AUTHOR]

Background: Noninvasive prenatal testing (NIPT) has been wildly used to screen for common aneuplodies. In recent years, the test has been expanded to detect rare autosomal aneuploidies (RATs) and copy number variations (CNVs). This study was performed to investigate the performance of expanded noninvasive prenatal testing (expanded NIPT) in screening for common trisomies, sex chromosomal aneuploidies (SCAs), rare autosomal aneuploidies (RATs), and copy number variations (CNVs) and parental willingness for invasive prenatal diagnosis in a Chinese prenatal diagnosis center. Methods: A total of 24,702 pregnant women were retrospectively analyzed at the Women and Children's Hospital from January 2013 to April 2019, among which expanded NIPT had been successfully conducted in 24,702 pregnant women. The high-risk expanded NIPT results were validated by karyotype analysis and chromosomal microarray analysis. All the tested pregnant women were followed up for pregnancy outcomes. Results: Of the 24,702 cases, successful follow-up was conducted in 98.77% (401/446) of cases with common trisomies and SCAs, 91.95% (80/87) of RAT and CNV cases, and 76.25% (18,429/24,169) of cases with low-risk screening results. The sensitivity of expanded NIPT was 100% (95% confidence interval[CI], 97.38–100%), 96.67%(95%CI, 82.78–99.92%), and 100%(95%CI, 66.37–100.00%), and the specificity was 99.92%(95%CI, 99.87–99.96%), 99.96%(95%CI, 99.91–99.98%), and 99.88% (95%CI, 99.82–99.93%) for the detection of trisomies 21, 18, and 13, respectively. Expanded NIPT detected 45,X, 47,XXX, 47,XXY, XYY syndrome, RATs, and CNVs with positive predictive values of 25.49%, 75%, 94.12%, 76.19%, 6.45%, and 50%, respectively. The women carrying fetuses with Trisomy 21/Trisomy 18/Trisomy 13 underwent invasive prenatal diagnosis and terminated their pregnancies at higher rates than those at high risk for SCAs, RATs, and CNVs. Conclusions: Our study demonstrates that the expanded NIPT detects fetal trisomies 21, 18, and 13 with high sensitivity and specificity. The accuracy of detecting SCAs, RATs, and CNVs is still relatively poor and needs to be improved. With a high-risk expanded NIPT result, the women at high risk for common trisomies are more likely to undergo invasive prenatal diagnosis procedures and terminate their pregnancies than those with unusual chromosome abnormalities. [ABSTRACT FROM AUTHOR]

Background: Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early‐onset non‐progressive involuntary movements. Although NKX2‐1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2‐1 gene, indicating that mutations of non‐coding regulatory elements of NKX2‐1 may also play a role. Methods and Results: By using whole‐genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2‐1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2‐1 on chromosome 14q13.2‐q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non‐coding sequences. Conclusion: We propose that the deletion of potential regulatory elements necessary for NKX2‐1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease‐causing mechanism for BHC. [ABSTRACT FROM AUTHOR]

Objective: Identification of large scale structural polymorphisms (Copy number variations) of more than 50 bp between the individuals of a species would help in knowing genetic diversity, phenotypic variability, adaptability to tropical environment and disease resistance., Methods: Read depth-based method implemented in CNVnator was used for calling copy number variant regions on sequenced data obtained from WGS from 15 pooled samples belonging to five draught cattle breeds of Tamil Nadu., Results: A total of 11,605 CNV regions (CNVRs) were observed covering a genome size of 18.63 percent. Among these, 11,459 were restricted to autosomes, consisting of 11,013 deletions, 353 duplications and 93 complex events. These CNVRs were annotated to 4,989 candidate genes. A total of 8,291 numbers of CNVRs were shared among the five cattle breeds as also supported by PCA and STRUCTURE analyses and 1,172 CNVRs were breed-specific. Four out of five selected breed-specific CNVRs were validated using real-time PCR. Genes with CNVRs are related to milk production (BTN1A1, ABCA1 and LAP3), disease resistance (TLR4 and DNAH8), adaptability (SOD1, CAST and SMARCAL1), growth (EGFR, NKAIN3), reproduction (BRWD1 and PDE6D), meat and carcass traits (MAP3K5 and NCAM1) and exterior (ATRN and MITF) traits. Gene enrichment analysis based on the gene list retrieved from the CNVRs disclosed over-represented terms (p<0.01) associated with milk fat production. NETWORK analysis had identified 13 putative candidate genes involved in milk fat percentage, milk fat yield, lactation persistency, milk yield, heat tolerance, calving ease, growth and conformation traits., Conclusion: The genome-wide CNVRs identified in the present study produced genome-wide partial CNV map in indigenous cattle breeds of Tamil Nadu.

Background and Objectives: Congenital heart defect (CHD) is one of the most common birth defects. The aim of this cohort study was to evaluate the prevalence of chromosomal abnormalities and the clinical utility of chromosomal microarray analysis (CMA) in fetuses with different types of CHD, aiming to assist genetic counseling and clinical decision-making., Methods: In this study, 642 fetuses with CHD were enrolled from a single center over a six-year period (2017-2022). Both conventional karyotyping and CMA were performed simultaneously on these fetuses., Results: The diagnostic yield of CMA in fetuses with CHD in our study was 15.3% (98/642). Our findings revealed a significant increase in the diagnostic yield of CMA compared to karyotyping in fetuses with CHD. Among CHD subgroups, the diagnostic yields were high in complex CHD (34.9%), conotruncal defects (28.6%), right ventricular outflow tract obstructive defects (RVOTO) (25.9%), atrioventricular septal defects (AVSD) (25.0%) and left ventricular outflow tract obstructive defects (LVOTO) (24.1%), while those in other CHD (10.6%) and septal defects (10.9%) were relatively low. The overall detection rate of clinically significant chromosomal abnormalities was significantly higher in the non-isolated CHD group compared to the isolated CHD group (33.1% vs. 9.9%, P < 0.0001). Interestingly, numerical chromosomal abnormalities were more likely to occur in the non-isolated CHD group than in the isolated CHD group (20.3% vs. 2.0%, P < 0.0001). The rate of termination of pregnancy (TOP)/Still birth in the non-isolated CHD group was significantly higher than that in the isolated CHD group (40.5% vs. 20.6%, P < 0.0001). Compared to the isolated CHD group, the detection rate of clinically significant chromosomal abnormalities was significantly higher in the group of CHD with soft markers (35.6% vs. 9.9%, P < 0.0001) and in the group of CHD with additional structural anomalies (36.1% vs. 9.9%, P < 0.0001)., Conclusions: CMA is a reliable and high-resolution technique that should be recommended as the front-line test for prenatal diagnosis of fetuses with CHD. The prevalence of chromosomal abnormalities varies greatly among different subgroups of CHD, and special attention should be given to prenatal non-isolated cases of CHD, especially those accompanied by additional structural anomalies or soft markers., (© 2024. The Author(s).)

Background: Chromosome 16p13.11 microdeletion is a very rare copy number variant (CNV), associated with a clinical syndrome characterized by global development delay, neuropsychiatric conditions, facial dysmorphisms, microcephaly, gastroesophageal reflux disease, and congenital heart defects. The 16p13.11 locus is a very unstable genomic region, rich in low-copy number repeats, characterized by many homologous DNA sequences. Usually, the most common CNV of this region include microduplications/duplications, while the microdeletions are rare, and their clinical features are heterogeneous and poorly described so far., Case Report: In this paper, we report the genetic and the clinical features of a patient diagnosed with chromosome 16p13.11 microdeletion, and a short review of the literature on this topic. Our patient was characterized by several facial dysmorphic features, autistic symptoms and language development delay. The genetic evaluation revealed and interstitial deletion of the long arm of the chromosome 16, approximately of 1.5 Mb., Conclusion: Interestingly, compared to previous cases, this patient was characterized by autistic symptoms, severe language and motor coordination disorder, without cognitive and cerebral malformations, frequently associated with this microdeletion syndrome., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Palumbi, Ponzi, Micella, Pascali, Bucci, Gentile, Margari and Simone.)

There are two key signatures of pediatric cancers: (a) higher prevalence of germline alterations and (b) heterogeneity in alteration types. Recent population-based assessments have demonstrated that children with birth defects (BDs) are more likely to develop cancer even without chromosomal anomalies; therefore, explorations of genetic alterations in children with BDs and cancers could provide new insights into the underlying mechanisms for pediatric tumor development. We performed whole-genome sequencing (WGS) on blood-derived DNA for 1556 individuals without chromosomal anomalies, including 454 BD probands with at least one type of malignant tumor, 757 cancer-free children with BDs, and 345 healthy individuals, focusing on copy number variation (CNV) analysis. Roughly half of the children with BD-cancer have CNVs that are not identified in BD-only/healthy individuals, and CNVs are not evenly distributed among these patients. Strong heterogeneity was observed, with a limited number of cancer predisposition genes containing CNVs in more than three patients. Moreover, functional enrichments of genes with CNVs showed that dozens of patients have variations related to the same biological pathways, such as deletions of genes with neurological functions and duplications of immune response genes. Phenotype clustering uncovered recurrences of patients with sarcoma: A notable enrichment was observed involving non-coding RNA regulators, showing strong signals related to growth and cancer regulations in functional analysis. In conclusion, we conducted one of the first genomic studies exploring the impact of CNVs on cancer development in children with BDs, unveiling new insights into the underlying biological processes., (© 2024 The Author(s). Molecular Oncology published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)

Low copy numbers (CNs) of C4 genes are associated with systemic autoimmune disorders and affects autoantibody diversity and disease subgroups. The primary objective of this study was to characterize diversity of complement (C4) and C4-Human Endogenous Retrovirus (HERV) gene copy numbers in SLE. We also sought to assess the association of C4 and C4-HERV CNs with serum complement levels, autoantibodies, disease phenotypes and activity. Finally, we checked the association of C4 and HERV CNs with specific HLA alleles. Genomic DNA from 70 SLE and 90 healthy controls of south Indian Tamil origin were included. Demographic, clinical and serological data was collected in a predetermined proforma. CNs of C4A and C4B genes and the frequency of insertion of 6.4kb HERV within C4 gene (C4AL, C4BL) was determined using droplet digital polymerase chain reaction (ddPCR). A four digit high resolution HLA genotyping was done using next generation sequencing. In our cohort, the total C4 gene copies ranged from 2 to 6. Compared to controls, presence of two or less copies of C4A gene was associated with SLE risk (p = 0.005; OR = 2.79; 95% CI = 1.29-6.22). Higher frequency of HERV insertion in C4A than in C4B increases such risk (p = 0.000; OR = 12.67; 95% CI = 2.80-115.3). AL-AL-AL-BS genotype was significantly higher in controls than SLE (9%vs1%, p = 0.04; OR = 0.15, 95% CI = 0.00-0.16). Distribution of HLA alleles was not different in SLE compared to controls as well as in SLE subjects with ≤ 2 copies and > 2 copies of C4A, but HLA allele distribution was diverse in subjects with C4B ≤ 2 copies and > 2 copies. Finally, there was no correlation between the C4 and the C4-HERV diversity and complement levels, autoantibodies, disease phenotypes and activity. In conclusion, our data show that, low C4A copy number and higher insertion of HERV-K in C4A increases the risk for SLE. C4 and C4-HERV CNs did not correlate with serum complements, autoantibodies, disease phenotypes and activity in SLE. Further validation in a larger homogenous SLE cohort is needed., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Schizophrenia is a neuropsychiatric disorder characterized by various symptoms such as hallucinations, delusions, and disordered thinking. The etiology of this disease is unknown; however, it has been linked to many microdeletion syndromes that are likely to contribute to the pathology of schizophrenia. In this review we have comprehensively analyzed the role of various microdeletion syndromes, like 3q29, 15q13.3, and 22q11.2, which are known to be involved with schizophrenia. A variety of factors lead to schizophrenia phenotypes, but copy number variants that disrupt gene regulation and impair brain function and cognition are one of the causes that have been identified. Multiple case studies have shown that loss of one or more genes in the microdeletion regions lead to brain activity defects. In this article, we present a coherent paradigm that connects copy number variations (CNVs) to numerous neurological and behavioral abnormalities associated with schizophrenia. It would be helpful in understanding the different aspects of the microdeletions and how they contribute in the pathophysiology of schizophrenia., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

With the gradual liberalization of the three-child policy and the development of assisted reproductive technology in China, the number of women with high-risk pregnancies is gradually increasing. In this study, 4211 fetuses who underwent chromosomal microarray analysis (CMA) with high-risk prenatal indications were analysed. The results showed that the overall prenatal detection rate of CMA was 11.4% (480/4211), with detection rates of 5.82% (245/4211) for abnormal chromosome numbers and 5.58% (235/4211) for copy number variants. Additionally, the detection rates of clinically significant copy number variants were 3.78% (159/4211) and 1.8% (76/4211) for variants of uncertain significance. The detection rates of fetal chromosomal abnormalities were 6.42% (30/467) for pregnant women with advanced maternal age (AMA), 6.01% (50/832) for high-risk maternal serum screening (MSS) results, 39.09% (224/573) with abnormal non-invasive prenatal testing (NIPT) results, 9.21% (127/1379) with abnormal ultrasound results, and 5.1% (49/960) for other indications. Follow-up results were available for 4211 patients, including 3677 (3677/4211, 87.32%) whose infants were normal after birth, 462 (462/4211, 10.97%) who terminated their pregnancy, 51 (51/4211, 1.21%) whose infants were abnormal after birth, and 21 (21/4211, 0.50%) who refused follow-up. The results of this study demonstrate significant variation in the diagnostic rate of chromosomal microarray analysis across different indications, providing valuable guidance for clinicians to assess the applicability of CMA technology in prenatal diagnosis., (© 2024. The Author(s).)

Background: Genetic disorders often manifest as abnormal fetal or childhood development. Copy number variations (CNVs) represent a significant genetic mechanism underlying such disorders. Despite their importance, the effectiveness of clinical exome sequencing (CES) in detecting CNVs, particularly small ones, remains incompletely understood. We aimed to evaluate the detection of both large and small CNVs using CES in a substantial clinical cohort, including parent-offspring trios and proband only analysis., Methods: We conducted a retrospective analysis of CES data from 2428 families, collected from 2018 to 2021. Detected CNV were categorized as large or small, and various validation techniques including chromosome microarray (CMA), Multiplex ligation-dependent probe amplification assay (MLPA), and/or PCR-based methods, were employed for cross-validation., Results: Our CNV discovery pipeline identified 171 CNV events in 154 cases, resulting in an overall detection rate of 6.3%. Validation was performed on 113 CNVs from 103 cases to assess CES reliability. The overall concordance rate between CES and other validation methods was 88.49% (100/113). Specifically, CES demonstrated complete consistency in detecting large CNV. However, for small CNVs, consistency rates were 81.08% (30/37) for deletions and 73.91% (17/23) for duplications., Conclusion: CES demonstrated high sensitivity and reliability in CNV detection. It emerges as an economical and dependable option for the clinical CNV detection in cases of developmental abnormalities, especially fetal structural abnormalities., (© 2024. The Author(s).)

Objective: To evaluate the accuracy of expanded noninvasive prenatal testing (NIPT) for maternal copy number variations., Materials and Methods: Expanded NIPT was used to detect CNVs ≥2 Mb at a whole-genome scale. The threshold of maternal deletion was copy numbers (CN) ≤ 1.6, and the threshold of maternal duplication was CN ≥ 2.4., Results: Of the 5440 pregnant women with successful expanded NIPT results, 28 maternal CNVs ≥2 Mb were detected in 27 pregnant women. Except for five cases reported as test failure, 23 CNVs ≥2 Mb were confirmed among the remaining 22 pregnant women by CNV-seq of maternal lymphocyte DNA. The genomic location, copy numbers and fragment size of maternal CNVs reported by expanded NIPT were consistent with the results of CNV-seq of maternal lymphocyte DNA., Conclusions: Maternal CNVs ≥2 Mb can be accurately evaluated according to the CN indicated by expanded NIPT results., Competing Interests: Conflicts of interest No financial or commercial conflicts of interest declared., (Copyright © 2024. Published by Elsevier B.V.)

Background: Structural variants (SVs) are currently analyzed using a combination of conventional methods; however, this approach has limitations. Optical genome mapping (OGM), an emerging technology for detecting SVs using a single-molecule strategy, has the potential to replace conventional methods. We compared OGM with conventional diagnostic methods for detecting SVs in various hematologic malignancies., Methods: Residual bone marrow aspirates from 27 patients with hematologic malignancies in whom SVs were observed using conventional methods (chromosomal banding analysis, FISH, an RNA fusion panel, and reverse transcription PCR) were analyzed using OGM. The concordance between the OGM and conventional method results was evaluated., Results: OGM showed concordance in 63% (17/27) and partial concordance in 37% (10/27) of samples. OGM detected 76% (52/68) of the total SVs correctly (concordance rate for each type of SVs: aneuploidies, 83% [15/18]; balanced translocation, 80% [12/15] unbalanced translocation, 54% [7/13] deletions, 81% [13/16]; duplications, 100% [2/2] inversion 100% [1/1]; insertion, 100% [1/1]; marker chromosome, 0% [0/1]; isochromosome, 100% [1/1]). Sixteen discordant results were attributed to the involvement of centromeric/telomeric regions, detection sensitivity, and a low mapping rate and coverage. OGM identified additional SVs, including submicroscopic SVs and novel fusions, in five cases., Conclusions: OGM shows a high level of concordance with conventional diagnostic methods for the detection of SVs and can identify novel variants, suggesting its potential utility in enabling more comprehensive SV analysis in routine diagnostics of hematologic malignancies, although further studies and improvements are required.