Relationship Between Gene-Phenotype and Clinical Manifestations of Chromosomal Copy Number Variations Indicated by Non-Invasive Prenatal Testing

Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.

Copy number variation of B1 controls awn length in wheat

Wheat awns contribute to photosynthesis and grain production.In this study,an F2population and F2:3families from a cross between the awned line 7D12 and the Chinese awnless variety Shiyou 20(SY20)were used to identify loci associated with awn length.Bulked-segregant RNA sequencing and linkage mapping identified a single dominant locus in a 0.3 cM interval on chromosome 5AL.Five genes were in the interval,including the recently cloned awn inhibitor B1.Although a single copy of the B1 gene was detected in 7D12,SY20 carried five copies of the gene.Increased copy number of B1 in SY20enhanced gene expression.Based on sequence variation among the promoter regions of five B1 gene copies in SY20,two dominant markers were developed and found to cosegregate with B1 in a population of 931 wheat accessions.All 77 awnless accessions harbored sequence variations in the B1 promoter regions similar to those of SY20 and thus carried multiple copies of the gene,whereas 15 randomly selected awned wheats carried only one copy.These results suggest that an increase in copy number of the B1 gene is associated with inhibition of awn length.

Copy number variation sequencing for diagnosis of cytomegalovirus infection based low-depth whole-genome sequencing technology in fetus:Three cases and literature review

Objective:To summarize the application value of copy number variant sequencing(CNV-seq)in the detection of fetal chromosome and cytomegalovirus load.Methods:The study analyzed the clinical basic data,relevant laboratory tests,treatment process,and outcomes of three patients with positive cytomegalovirus load detected by CNV-seq for fetal chromosomes and cytomegalovirus load,and literature review was done simutaneoubly.Results:In all three cases,the amniotic fluid cytomegalovirus load was less than 105 Copies/ml,and there were no significant neurological abnormalities observed during pregnancy or postpartum follow-up.There is no literature review on the application of CNV-seq technology in the detection of cytomegalovirus infection,only literature reports on genome analysis of CMV-DNA in confirmed patients were available.Conclusion:CNV-seq can be used to detect cytomegalovirus load,which may have a certain degree of predictive value for fetal outcome.CNV-seq can simultaneously detect fetal chromosomes and pathogenic microorganisms,which is of great significance for the prevention and control of birth defects.

Low-depth whole genome sequencing reveals copy number variations associated with higher pathologic grading and more aggressive subtypes of lung non-mucinous adenocarcinoma

Objective:Histology grade,subtypes and TNM stage of lung adenocarcinomas are useful predictors of prognosis and survival.The aim of the study was to investigate the relationship between chromosomal instability,morphological subtypes and the grading system used in lung non-mucinous adenocarcinoma(LNMA).Methods:We developed a whole genome copy number variation(WGCNV)scoring system and applied next generation sequencing to evaluate CNVs present in 91 LNMA tumor samples.Results:Higher histological grades,aggressive subtypes and more advanced TNM staging were associated with an increased WGCNV score,particularly in CNV regions enriched for tumor suppressor genes and oncogenes.In addition,we demonstrate that 24-chromosome CNV profiling can be performed reliably from specific cell types(<100 cells)isolated by sample laser capture microdissection.Conclusions:Our findings suggest that the WGCNV scoring system we developed may have potential value as an adjunct test for predicting the prognosis of patients diagnosed with LNMA.

Scan of the endogenous retrovirus sequences across the swine genome and survey of their copy number variation and sequence diversity among various Chinese and Western pig breeds

In pig-to-human xenotransplantation,the transmission risk of porcine endogenous retroviruses(PERVs)is of great concern.However,the distribution of PERVs in pig genomes,their genetic variation among Eurasian pigs,and their evolutionary history remain unclear.We scanned PERVs in the current pig reference genome(assembly Build 11.1),and identified 36 long complete or near-complete PERVs(lc PERVs)and 23 short incomplete PERVs(si PERVs).Besides three known PERVs(PERV-A,-B,and-C),four novel types(PERV-JX1,-JX2,-JX3,and-JX4)were detected in this study.According to evolutionary analyses,the newly discovered PERVs were more ancient,and PERV-Bs probably experienced a bottleneck~0.5 million years ago(Ma).By analyzing63 high-quality porcine whole-genome resequencing data,we found that the PERV copy numbers in Chinese pigs were lower(32.0±4.0)than in Western pigs(49.1±6.5).Additionally,the PERV sequence diversity was lower in Chinese pigs than in Western pigs.Regarding the lc PERV copy numbers,PERV-A and-JX2 in Western pigs were higher than in Chinese pigs.Notably,Bama Xiang(BMX)pigs had the lowest PERV copy number(27.8±5.1),and a BMX individual had no PERV-C and the lowest PERV copy number(23),suggesting that BMX pigs were more suitable for screening and/or modification as xenograft donors.Furthermore,we identified 451 PERV transposon insertion polymorphisms(TIPs),of which 86 were shared by all 10 Chinese and Western pig breeds.Our findings provide systematic insights into the genomic distribution,variation,evolution,and possible biological function of PERVs.

Association between TLR7 copy number variations and hepatitis B virus infection outcome in Chinese

AIM To explore whether copy number variations (CNVs) of toll-like receptor 7 (TLR7) are associated with susceptibility to chronic hepatitis B virus (HBV) infection. METHODS This study included 623 patients (495 males and 128 females) with chronic hepatitis B virus infection (CHB) and 300 patients (135 females and 165 males) with acute hepatitis B virus infection (AHB) as controls. All CHB patients were further categorized according to disease progression after HBV infection (CHB, liver cirrhosis, or hepatocellular carcinoma). Copy numbers of the TLR7 gene were measured using the AccuCopy method chi(2) tests were used to evaluate the association between TLR7 CNVs and infection type. P values, odds ratios, and 95% confidence intervals (CIs) were used to estimate the effects of risk. RESULTS Among male patients, there were significant differences between the AHB group and CHB group in the distribution of TLR7 CNVs. Low copy numberof TLR7 was significantly associated with chronic HBV infection (OR = 0.329, 95% CI: 0.229-0.473, P > 0.001). Difference in TLR7 copy number was also found between AHB and CHB female patients, with low copy number again associated with an increased risk of chronic HBV infection (OR = 0.292, 95% CI: 0.173- 0.492, P < 0.001). However, there were no significant differences in TLR7 copy number among the three types of chronic HBV infection (CHB, liver cirrhosis, or hepatocellular carcinoma). In addition, there was no association between TLR7 copy number and titer of the HBV e antigen. CONCLUSION Low TLR7 copy number is a risk factor for chronic HBV infection but is not associated with later stages of disease progression.

AB015.The relationship between copy number variations and high myopia in Chinese:a case-control study

As a complex disease,myopia is the most common eye disease worldwide.Many myopia susceptibility genes or variants have been successfully identified in the past years by genome-wide genetic association studies(GWAS),which focus mainly on the single-nucleotide polymorphisms.Little attention has been paid to examine the role of copy number variations(CNVs)in refractive error and myopia.This study adopted a systematic strategy to investigate the role of CNVs in high myopia.In the discovery phase,a pilot GWAS suggests putative CNVs for follow-up.Multiplex ligation-dependent probe amplification was then used to quantify the copy number of 89 CNV segments in 737 case-control samples in the second phase and then 24 top-ranking CNVs in a second group of 1,029 case-control samples in the final validation phase.This validation phase identified 22 significant CNVs.Further work is needed to examine the role of these few CNVs in myopia development.

SMARCC1 copy number variation is related to metastatic colon cancer:an investigation based on TCGA data

Objective There are no well-defined genetic indicators for distant metastatic illness in patients with colon cancer(CC).The discovery of genetic changes linked to metastatic CC might aid in the development of systemic and local therapeutic approaches.Using The Cancer Genome Atlas(TCGA),we examined the relationship between copy number variation(CNV)of SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily C member 1(SMARCC1)and distant metastatic illness in patients with CC.Methods Genetic sequencing data of all relevant CC patients and clinical features were collected from TCGA using R.There were 506 CC patients with CNV and clinical outcome data.The CNV of SMARCC1 was examined for its correlation with distant metastatic disease using the TCGA CC dataset(M1 vs.M0).After adjusting for age,sex,T stage,N stage,adjuvant chemotherapy,microsatellite instability(MSI),and surgical margin status,univariate and multivariate logistic regression analyses were performed.Results SMARCC1 CNV was linked to distant metastatic disease(P=0.012 and 0.008 in univariate and multivariate analysis,respectively);positive lymph nodes and margin status were also associated with distal metastases(all P<0.01).MSI,T stage,N stage,adjuvant treatment,sex,race,and MSI were not associated with metastases(all P>0.05).Conclusion SMARCC1 CNV is associated with distant metastatic disease in patients with CC.In individuals with CC,such genetic profiles might be utilized therapeutically to support optimal systemic treatment options against local treatments for CC,such as radiation therapy,pending additional confirmation.

Genetic Copy Number Variations in Colon Mucosa Indicating Risk for Colorectal Cancer

Background: Sporadic colorectal tumors probably carry genetic alterations that may be related to familiar clusters according to risk loci visualized by SNP arrays on normal tissues. The aim of the present study was therefore to search for DNA regions (copy number variations, CNVs) as biomarkers associated to genetic susceptibility for early risk predictions of colorectal cancer. Such sequence alterations could provide additional information on phenotypic grouping of patients. Material and Methods: High resolution 105K oligonucleotide microarrays were used in search for CNV loci in DNA from tumor-free colon mucosa at primary operations for colon cancer in 60 unselected patients in comparison to DNA in buffy coat cells from 44 confirmed tumor-free and healthy blood donors. Array-detected CNVs were confirmed by Multiplex ligation-dependent probe amplification (MLPA). Results: A total number of 205 potential CNVs were present in DNA from colon mucosa. 184 (90%) of the 205 potential CNVs had been identified earlier in mucosa DNA from healthy individuals as reported to the Database of Genomic Variants. Remaining 21 (10%) CNVs were potentially novel sites. Two CNVs (3q23 and 10q21.1) were significantly related to colon cancer, but not confirmed in buffy coat DNA from the cancer patients. Conclusion: Our study reveals two CNVs that indicate increased risk for colon cancer;These DNA alterations may have? been acquired by colon stem cells with subsequent appearance among epithelial mucosa cells. Impact: Certain mucosa CNV alterations may indicate individual susceptibility for malignant transformation in relationship to intestinal toxins and bacterial growth.

Somatic CDKN2A copy number variations are associated with the prognosis of esophageal squamous cell dysplasia

Background:Somatic copy number variations(SCNVs)in the CDKN2A gene are among the most frequent events in the dysplasia-carcinoma sequence of esophageal squamous cell carcinoma.However,whether CDKN2A SCNVs are useful biomarkers for the risk stratification and management of patients with esophageal squamous cell dysplasia(ESCdys)is unknown.This study aimed to investigate the characteristics and prognostic value of CDKN2A SCNVs in patients with mild or moderate(m/M)ESCdys.Methods:This study conducted a prospective multicenter study of 205 patients with a baseline diagnosis of m/M ESCdys in five high-risk regions of China(Ci County,Hebei Province;Yanting,Sichuan Province;Linzhou,Henan Province;Yangzhong,Jiangsu Province;and Feicheng,Shandong Province)from 2005 to 2019.Genomic DNA was extracted from paraffin biopsy samples and paired peripheral white blood cells from patients,and a quantitative polymerase chain reaction assay,P16-Light,was used to detect CDKN2A copy number.The cumulative regression and progression rates of ESCdys were evaluated using competing risk models.Results:A total of 205 patients with baseline m/M ESCdys were enrolled.The proportion of ESCdys regression was significantly lower in the CDKN2A deletion cohort than in the diploid and amplification cohorts(18.8%[13/69]vs.35.0%[28/80]vs.51.8%[29/56],P<0.001).In the univariable competing risk analysis,the cumulative regression rate was statistically significantly lower(P=0.008),while the cumulative progression rate was higher(P=0.017)in ESCdys patients with CDKN2A deletion than in those without CDKN2A deletion.CDKN2A deletion was also an independent predictor of prognosis in ESCdys(P=0.004)in the multivariable analysis.Conclusion:The results indicated that CDKN2A SCNVs are associated with the prognosis of ESCdys and may serve as potential biomarkers for risk stratification.

Association of copy number variation in X chromosome-linked PNPLA4 with heterotaxy and congenital heart disease

Background:Heterotaxy(HTX)is a thoracoabdominal organ anomaly syndrome and commonly accompanied by congenital heart disease(CHD).The aim of this study was to analyze rare copy number variations(CNVs)in a HTX/CHD cohort and to examine the potential mechanisms contributing to HTX/CHD.Methods:Chromosome microarray analysis was used to identify rare CNVs in a cohort of 120 unrelated HTX/CHD patients,and available samples from parents were used to confirm the inheritance pattern.Potential candidate genes in CNVs region were prioritized via the DECIPHER database,and PNPLA4 was identified as the leading candidate gene.To validate,we generated PNPLA4-overexpressing human induced pluripotent stem cell lines as well as pnpla4-overexpressing zebrafish model,followed by a series of transcriptomic,biochemical and cellular analyses.Results:Seventeen rare CNVs were identified in 15 of the 120 HTX/CHD patients(12.5%).Xp22.31 duplication was one of the inherited CNVs identified in this HTX/CHD cohort,and PNPLA4 in the Xp22.31 was a candidate gene associated with HTX/CHD.PNPLA4 is expressed in the lateral plate mesoderm,which is known to be critical for left/right embryonic patterning as well as cardiomyocyte differentiation,and in the neural crest cell lineage.Through a series of in vivo and in vitro analyses at the molecular and cellular levels,we revealed that the biological function of PNPLA4 is importantly involved in the primary cilia formation and function via its regulation of energy metabolism and mitochondria-mediated ATP production.Conclusions:Our findings demonstrated a significant association between CNVs and HTX/CHD.Our data strongly suggested that an increased genetic dose of PNPLA4 due to Xp22.31 duplication is a disease-causing risk factor for HTX/CHD.

Next‑Generation Sequencing‑Based Copy Number Variation Analysis in Chinese Patients with Primary Ciliary Dyskinesia Revealed Novel DNAH5 Copy Number Variations

Primary ciliary dyskinesia(PCD)is a rare disorder characterized by extensive genetic heterogeneity.However,in the genetic pathogenesis of PCD,copy number variation(CNV)has not received sufcient attention and has rarely been reported,especially in China.Next-generation sequencing(NGS)followed by targeted CNV analysis was used in patients highly suspected to have PCD with negative results in routine whole-exome sequencing(WES)analysis.Quantitative real-time polymerase chain reaction(qPCR)and Sanger sequencing were used to confrm these CNVs.To further characterize the ciliary phenotypes,high-speed video microscopy analysis(HSVA),transmission electron microscopy(TEM),and immunofuorescence(IF)analysis were used.Patient 1(F1:II-1),a 0.6-year-old girl,came from a nonconsanguineous family-I.She presented with situs inversus totalis,neonatal respiratory distress,and sinusitis.The nasal nitric oxide level was markedly reduced.The respiratory cilia beat with reduced amplitude.TEM revealed shortened outer dynein arms(ODA)of cilia.chr5:13717907-13722661del spanning exons 71–72 was identifed by NGS-based CNV analysis.Patient 2(F2:IV-4),a 37-year-old man,and his eldest brother Patient 3(F2:IV-2)came from a consanguineous family-II.Both had sinusitis,bronchiectasis and situs inversus totalis.The respiratory cilia of Patient 2 and Patient 3 were found to be uniformly immotile,with ODA defects.Two novel homozygous deletions chr5:13720087_13733030delinsGTTTTC and chr5:13649539_13707643del,spanning exons 69–71 and exons 77–79 were identifed by NGS-based CNV analysis.Abnormalities in DNA copy number were confrmed by qPCR amplifcation.IF showed that the respiratory cilia of Patient 1 and Patient 2 were defcient in dynein axonemal heavy chain 5(DNAH5)protein expression.This report identifed three novel DNAH5 disease-associated variants by WES-based CNV analysis.Our study expands the genetic spectrum of PCD with DNAH5 in the Chinese population.

Clinical significance of germline copy number variation in susceptibility of human diseases

Germline copy number variation （CNV） is considered to be an important form of human genetic poly- morphisms. Previous studies have identified amounts of CNVs in human genome by advanced technologies, such as comparative genomic hybridization, single nucleotide genotyping, and high-throughput sequencing. CNV is speculated to be derived from multiple mechanisms, such as nonallelic homologous recombination （NAHR） and nonhomologous end-joining （NHEJ）. CNVs cover a much larger genome scale than single nucleotide polymorphisms （SNPs）, and may alter gene expression levels by means of gene dosage, gene fusion, gene disruption, and long-range regulation effects, thus affecting individual phenotypes and playing crucial roles in human pathogenesis. The number of studies linking CNVs with common complex diseases has increased dramatically in recent years. Here, we provide a comprehensive review of the current understanding ofgermline CNVs, and summarize the association of germline CNVs with the susceptibility to a wide variety of human diseases that were identified in recent years. We also propose potential issues that should be addressed in future studies.

Autism spectrum disorder model mice: Focus on copy number variation and epigenetics

Autism spectrum disorder(ASD) is gathering concerns in socially developed countries. ASD is a neuropsychiatric disorder of genetic origin with high prevalence of 1%–2%. The patients with ASD characteristically show impaired social skills. Today, many genetic studies identify numerous susceptible genes and genetic loci associated with ASD. Although some genetic factors can lead to abnormal brain function linked to ASD phenotypes, the pathogenic mechanism of ASD is still unclear. Here, we discuss a new mouse model for ASD as an advanced tool to understand the mechanism of ASD.

De novel heterozygous copy number deletion on 7q31.31-7q31.32 involving TSPAN12 gene with familial exudative vitreoretinopathy in a Chinese family

AIM:To investigate the genetic and clinical characteristics of patients with a large heterozygous copy number deletion on 7q31.31-7q31.32.METHODS:A family with familial exudative vitreoretinopathy(FEVR)phenotype was included in the study.Whole-exome sequencing(WES)was initially used to locate copy number variations(CNVs)on 7q31.31-31.32,but failed to detect the precise breakpoint.The long-read sequencing,Oxford Nanopore sequencing Technology(ONT)was used to get the accurate breakpoint which is verified by quantitative real-time polymerase chain reaction(QPCR)and Sanger Sequencing.RESULTS:The proband,along with her father and younger brother,were found to have a heterozygous 4.5 Mb CNV deletion located on 7q31.31-31.32,which included the FEVRrelated gene TSPAN12.The specific deletion was confirmed as del(7)(q31.31q31.32)chr7:g.119451239_123956818del.The proband exhibited a phase 2A FEVR phenotype,characterized by a falciform retinal fold,macular dragging,and peripheral neovascularization with leaking of fluorescence.These symptoms led to a significant decrease in visual acuity in both eyes.On the other hand,the affected father and younger brother showed a milder phenotype.CONCLUSION:The heterozygous CNV deletion located on 7q31.31-7q31.32 is associated with the FEVR phenotype.The use of long-read sequencing techniques is essential for accurate molecular diagnosis of genetic disorders.

Integrative analysis of prognostic long non-coding RNAs with copy number variation in bladder cancer

Copy number variations(CNVs), which can affect the role of long non-coding RNAs(lncRNAs), are important genetic changes seen in some malignant tumors. We analyzed lncRNAs with CNV to explore the relationship between lncRNAs and prognosis in bladder cancer(BLCA). Messenger RNA(mRNA) expression levels, DNA methylation, and DNA copy number data of 408 BLCA patients were subjected to integrative bioinformatics analysis. Cluster analysis was performed to obtain different subtypes and differently expressed lncRNAs and coding genes. Weighted gene co-expression network analysis(WGCNA) was performed to identify the co-expression gene and lncRNA modules. CNV-associated lncRNA data and their influence on cancer prognosis were assessed with Kaplan-Meier survival curve. Multi-omics integration analysis revealed five prognostic lncRNAs with CNV, namely NR2 F1-AS1, LINC01138, THUMPD3-AS1, LOC101928489, and TMEM147-AS1, and a risk-score signature related to overall survival in BLCA was identified. Moreover, validated results in another independent Gene Expression Omnibus(GEO) dataset, GSE31684, were consistent with these results. Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis revealed that the mitogen-activated protein kinase(MAPK) signaling pathway, focal adhesion pathway, and Janus kinase-signal transducers and activators of transcription(JAK-STAT) signaling pathway were enriched in a high-risk score pattern, suggesting that imbalance in these pathways is closely related to tumor development. We revealed the prognosis-related lncRNAs by analyzing the expression profiles of lncRNAs and CNVs, which can be used as prognostic biomarkers for BLCA.

Measurement of copy number variation in single cancer cells using rapid-emulsification digital droplet MDA

Uniform amplification of low-input DNA is important for applications across biology,including single-cell genomics,forensic science,and microbial and viral sequencing.However,the requisite biochemical amplification methods are prone to bias,skewing sequence proportions and obscuring signals relating to copy number.Digital droplet multiple displacement amplification enables uniform amplification but requires expert knowledge of microfluidics to generate monodisperse emulsions.In addition,existing microfluidic methods are tedious and labor intensive for preparing many samples.Here,we introduce rapid-emulsification multiple displacement amplification,a method to generate monodisperse droplets with a hand-held syringe and hierarchical droplet splitter.Although conventional microfluidic devices require >10 min to emulsify a sample,our system requires tens of seconds and yields data of equivalent quality.We demonstrate the approach by using it to accurately measure copy number variation(CNV)in single cancer cells.

Copy number variation profile-based genomic typing of premenstrual dysphoric disorder in Chinese

Premenstrual dysphoric disorder(PMDD) affects nearly 5% of women of reproductive age. Symptomatic heterogeneity, together with largely unknown genetics, has greatly hindered its effective treatment. In the present study, analysis of genomic sequencing-based copy number variations(CNVs) called from 100 kb white blood cell DNA sequence windows by means of semisupervized clustering led to the segregation of patient genomes into the D and V groups, which correlated with the depression and invasion clinical types,respectively, with 89.0% consistency. Application of diagnostic CNV features selected using the correlation-based machine learning method enabled the classification of the CNVs obtained into the D group, V group, total patient group, and control group with an average accuracy of 83.0%. The power of the diagnostic CNV features was 0.98 on average, suggesting that these CNV features could be used for the molecular diagnosis of the major clinical types of PMDD. This demonstrated concordance between the CNV profiles and clinical types of PMDD supported the validity of symptom-based diagnosis of PMDD for differentiating between its two major clinical types, as well as the predominantly genetic nature of PMDD with a host of overlaps between multiple susceptibility genes/pathways and the diagnostic CNV features as indicators of involvement in PMDD etiology.

A Rare Novel Copy Number Variation of Xp22.33-p11.22 Duplication is Associated with Congenital Heart Defects

Congenital heart defect （CHD） is the most common fetal defects. Copy nmnber variations （CNVs） were demonstrated to be involved in the etiology of CHDs. We report three cases from a family diagnosed as CHDs with a rare novel duplication ofXp22.33-p I 1.22. A 30-year-old woman, gmvida 2 para 0. Her first pregnancy at 2012 was diagnosed to be dichorionic twin pregnancy and her second pregnancy at 2014 was a singleton pregnancy. After a routine ultrasound scan at 22 week＇s gestation, all the fetuses were diagnosed with critical CHDs. The first fetus （male） exhibited tetralogy of Fallot, atrial septal defect, persistent left superior vena cava, and coronary sinus dilatation while the examination of the second fetus （male） revealed atrioventricular septal detect and hypoplastic left heart syndrome. The third fetus （t^male） was also diagnosed with an atrioventricular septaI defect and hypoplastic left heart syndrome. The parents decided to terminate the wegnancy.

CNVbase:Batch identification of novel and rare copy number variations based on multi-ethnic population data

Human genetic variants have long been known to play an important role in both Mendelian disorders and common diseases. Notably, pathogenic variants are not limited to single-nucleotide variants. It has become apparent that human diseases can also be caused by copy number variations （CNVs）, especially patient- specific novel CNVs （lafrate et al., 2004; Sebat et al., 2004; Redon et al., 2006; LuDski, 2007; Zhan~ et al.. 2009： Wu et al.. 2015）.