Detection of clinically relevant copy-number variants by exome sequencing in a large cohort of genetic disorders

PurposeCopy-number variation is a common source of genomic variation and an important genetic cause of disease. Microarray-based analysis of copy-number variants (CNVs) has become a first-tier diagnostic test for patients with neurodevelopmental disorders, with a diagnostic yield of 10–20%. However, for most other genetic disorders, the role of CNVs is less clear and most diagnostic genetic studies are generally limited to the study of single-nucleotide variants (SNVs) and other small variants. With the introduction of exome and genome sequencing, it is now possible to detect both SNVs and CNVs using an exome- or genome-wide approach with a single test.MethodsWe performed exome-based read-depth CNV screening on data from 2,603 patients affected by a range of genetic disorders for which exome sequencing was performed in a diagnostic setting.ResultsIn total, 123 clinically relevant CNVs ranging in size from 727 bp to 15.3 Mb were detected, which resulted in 51 conclusive diagnoses and an overall increase in diagnostic yield of ~2% (ranging from 0 to –5.8% per disorder).ConclusionsThis study shows that CNVs play an important role in a broad range of genetic disorders and that detection via exome-based CNV profiling results in an increase in the diagnostic yield without additional testing, bringing us closer to single-test genomics.Genet Med advance online publication 27 October 2016     

Toward an effective exome-based genetic testing strategy in pediatric dilated cardiomyopathy

PurposeWe evaluated the diagnostic yield in pediatric dilated cardiomyopathy (DCM) of combining exome sequencing (ES)-based targeted analysis and genome-wide copy-number variation (CNV) analysis. Based on our findings, we retrospectively designed an effective approach for genetic testing in pediatric DCM.MethodsWe identified 95 patients (in 85 families) with pediatric onset of DCM. We initially excluded 13 of these families because they already had a genetic diagnosis, leaving a total of 31 probands for single-nucleotide polymorphism (SNP) array and trio-ES. We used Human Phenotype Ontology (HPO)-based filtering for our data analysis.ResultsWe reached a genetic diagnosis in 15/31 (48.4%) families. ES yielded a diagnosis in 13 probands (13/15; 86.7%), with most variants being found in genes encoding structural cardiomyocyte components. Two large deletions were identified using SNP array. If we had included the 13 excluded families, our estimated yield would have been 54%.ConclusionWe propose a standardized, stepwise analysis of (i) well-known cardiomyopathy genes, (ii) CNVs, (iii) all genes assigned to HPO cardiomyopathy, and (iv) if appropriate, genes assigned to other HPO terms. This diagnostic approach yields the highest increase at each subsequent step and reduces analytic effort, cost, the number of variants of unknown clinical significance, and the chance of incidental findings.     

Prenatal exome sequencing in anomalous fetuses: new opportunities and challenges

PurposeWe investigated the diagnostic and clinical performance of exome sequencing in fetuses with sonographic abnormalities with normal karyotype and microarray and, in some cases, normal gene-specific sequencing.MethodsExome sequencing was performed on DNA from 15 anomalous fetuses and from the peripheral blood of their parents. Parents provided consent to be informed of diagnostic results in the fetus, medically actionable findings in the parents, and their identification as carrier couples for significant autosomal recessive conditions. We assessed the perceptions and understanding of exome sequencing using mixed methods in 15 mother−father dyads.ResultsIn seven (47%) of 15 fetuses, exome sequencing provided a diagnosis or possible diagnosis with identification of variants in the following genes: COL1A1, MUSK, KCTD1, RTTN, TMEM67, PIEZO1 and DYNC2H1. One additional case revealed a de novo nonsense mutation in a novel candidate gene (MAP4K4). The perceived likelihood that exome sequencing would explain the results (5.2 on a 10-point scale) was higher than the approximately 30% diagnostic yield discussed in pretest counseling.ConclusionExome sequencing had diagnostic utility in a highly select population of fetuses where a genetic diagnosis was highly suspected. Challenges related to genetics literacy and variant interpretation must be addressed by highly tailored pre- and posttest genetic counseling.     

Enhanced utility of family-centered diagnostic exome sequencing with inheritance model–based analysis: results from 500 unselected families with undiagnosed genetic conditions

PurposeDiagnostic exome sequencing was immediately successful in diagnosing patients in whom traditional technologies were uninformative. Herein, we provide the results from the first 500 probands referred to a clinical laboratory for diagnostic exome sequencing.MethodsFamily-based exome sequencing included whole-exome sequencing followed by family inheritance−based model filtering, comprehensive medical review, familial cosegregation analysis, and analysis of novel genes.ResultsA positive or likely positive result in a characterized gene was identified in 30% of patients (152/500). A novel gene finding was identified in 7.5% of patients (31/416). The highest diagnostic rates were observed among patients with ataxia, multiple congenital anomalies, and epilepsy (44, 36, and 35%, respectively). Twenty-three percent of positive findings were within genes characterized within the past 2 years. The diagnostic rate was significantly higher among families undergoing a trio (37%) as compared with a singleton (21%) whole-exome testing strategy.ConclusionOverall, we present results from the largest clinical cohort of diagnostic exome sequencing cases to date. These data demonstrate the utility of family-based exome sequencing and analysis to obtain the highest reported detection rate in an unselected clinical cohort, illustrating the utility of diagnostic exome sequencing as a transformative technology for the molecular diagnosis of genetic disease.Genet Med 17 7, 578–586.     

Copy-number variation contributes 9% of pathogenicity in the inherited retinal degenerations

PurposeCurrent sequencing strategies can genetically solve 55–60% of inherited retinal degeneration (IRD) cases, despite recent progress in sequencing. This can partially be attributed to elusive pathogenic variants (PVs) in known IRD genes, including copy-number variations (CNVs), which have been shown as major contributors to unsolved IRD cases.MethodsFive hundred IRD patients were analyzed with targeted next-generation sequencing (NGS). The NGS data were used to detect CNVs with ExomeDepth and gCNV and the results were compared with CNV detection with a single-nucleotide polymorphism (SNP) array. Likely causal CNV predictions were validated by quantitative polymerase chain reaction (qPCR).ResultsLikely disease-causing single-nucleotide variants (SNVs) and small indels were found in 55.6% of subjects. PVs in USH2A (11.6%), RPGR (4%), and EYS (4%) were the most common. Likely causal CNVs were found in an additional 8.8% of patients. Of the three CNV detection methods, gCNV showed the highest accuracy. Approximately 30% of unsolved subjects had a single likely PV in a recessive IRD gene.ConclusionCNV detection using NGS-based algorithms is a reliable method that greatly increases the genetic diagnostic rate of IRDs. Experimentally validating CNVs helps estimate the rate at which IRDs might be solved by a CNV plus a more elusive variant.     

Mobile element insertion detection in 89,874 clinical exomes

PurposeExome sequencing (ES) is increasingly used for the diagnosis of rare genetic disease. However, some pathogenic sequence variants within the exome go undetected due to the technical difficulty of identifying them. Mobile element insertions (MEIs) are a known cause of genetic disease in humans but have been historically difficult to detect via ES and similar targeted sequencing methods.MethodsWe developed and applied a novel MEI detection method prospectively to samples received for clinical ES beginning in November 2017. Positive MEI findings were confirmed by an orthogonal method and reported back to the ordering provider. In this study, we examined 89,874 samples from 38,871 cases.ResultsDiagnostic MEIs were present in 0.03% (95% binomial test confidence interval: 0.02–0.06%) of all cases and account for 0.15% (95% binomial test confidence interval: 0.08–0.25%) of cases with a molecular diagnosis. One diagnostic MEI was a novel founder event. Most patients with pathogenic MEIs had prior genetic testing, three of whom had previous negative DNA sequencing analysis of the diagnostic gene.ConclusionMEI detection from ES is a valuable diagnostic tool, reveals molecular findings that may be undetected by other sequencing assays, and increases diagnostic yield by 0.15%.     

Putting genome-wide sequencing in neonates into perspective

PurposeSeveral studies have reported diagnostic yields up to 57% for rapid exome or genome sequencing (rES/GS) as a single test in neonatal intensive care unit (NICU) patients, but the additional yield of rES/GS compared with other available diagnostic options still remains unquantified in this population.MethodsWe retrospectively evaluated all genetic NICU consultations in a 2-year period.ResultsIn 132 retrospectively evaluated NICU consultations 27 of 32 diagnoses (84.4%) were made using standard genetic workup. Most diagnoses (65.6%) were made within 16 days. Diagnostic ES yield was 5/29 (17.2%). Genetic diagnoses had a direct effect on clinical management in 90.6% (29/32) of patients.ConclusionsOur study shows that exome sequencing has a place in NICU diagnostics, but given the associated costs and the high yield of alternative diagnostic strategies, we recommend to first perform clinical genetic consultation.     

Rapid exome sequencing in critically ill children impacts acute and long-term management of patients and their families: A retrospective regional evaluation

IntroductionGenetic disorders are a significant cause of paediatric morbidity and mortality. Rapid exome sequencing was introduced by the National Health Service (NHS) in England on 1^st October 2019 for acutely unwell children with a likely monogenic disorder, or to inform current pregnancy management where there was a previously affected child or fetus. We present results of a 12-month patient cohort from one large clinical genetics centre in England.MethodsPatients were identified through local genetics laboratory records. We included all cases which underwent rapid exome sequencing between 1^st October 2020 and 30^th September 2021. DNA was extracted, quality checked and exported to the Exeter Genomic laboratory where library preparation, exome sequencing of all known human genes, gene-agnostic bioinformatic analysis, variant interpretation, MDT discussions and reporting were performed.ResultsNinety-five probands were included. Trio analysis was performed in 90% (85), duo in 8% (8), singleton in 2% (2). The median turnaround time for preliminary reports was 11 days. The overall diagnostic yield was 40% (38 patients); 36% (34 patients) made solely on exome with a further 4% on concomitant exome and microarray analysis. Highest diagnostic rates were seen in patients with neuro-regression, skeletal dysplasia, neuromuscular and neurometabolic conditions.Where the diagnosis was made solely through exome sequencing, management was altered for the proband or family in 97% (33/34). For the proband, this was most commonly that the diagnosis was able to inform current management and prognosis (20 patients, 59%), as well as direct specialist referrals (10 patients, 29%). For families, the exome sequencing results provided accurate recurrence risk counselling in 88% (30/34) with cascade testing offered if indicated in some families.ConclusionsIn the majority of cases, the genetic diagnoses influenced acute and long-term management for critically ill children and their families. Paediatric and neonatal clinicians in the NHS now have direct access to exome sequencing for their patients. The rapid turnaround time was particularly helpful to alter the management in acute clinical settings and is a powerful tool for diagnosing monogenic conditions. This study is an example of a highly successful integration of a national rapid exome sequencing service with diagnostic rates comparable to previously reported literature.     

Low-pass whole-genome sequencing in clinical cytogenetics: a validated approach

PurposeChromosomal microarray analysis is the gold standard for copy-number variant (CNV) detection in prenatal and postnatal diagnosis. We aimed to determine whether next-generation sequencing (NGS) technology could be an alternative method for CNV detection in routine clinical application.MethodsGenome-wide CNV analysis (>50 kb) was performed on a multicenter group of 570 patients using a low-coverage whole-genome sequencing pipeline. These samples were referred for chromosomal analysis; CNVs (i.e., pathogenic CNVs, pCNVs) were classified according to the American College of Medical Genetics and Genomics guidelines.ResultsOverall, a total of 198 abortuses, 37 stillbirths, 149 prenatal, and 186 postnatal samples were tested. Our approach yielded results in 549 samples (96.3%). In addition to 119 subjects with aneuploidies, 103 pCNVs (74 losses and 29 gains) were identified in 82 samples, giving diagnostic yields of 53.2% (95% confidence interval: 45.8, 60.5), 14.7% (5.0, 31.1), 28.5% (21.1, 36.6), and 30.1% (23.6, 37.3) in each group, respectively. Mosaicism was observed at a level as low as 25%.ConclusionsPatients with chromosomal diseases or microdeletion/microduplication syndromes were diagnosed using a high-resolution genome-wide method. Our study revealed the potential of NGS to facilitate genetic diagnoses that were not evident in the prenatal and postnatal groups.Genet Med 18 9, 940–948.     

Artificial intelligence (AI)-assisted exome reanalysis greatly aids in the identification of new positive cases and reduces analysis time in a clinical diagnostic laboratory

PurposeArtificial intelligence (AI) and variant prioritization tools for genomic variant analysis are being rapidly developed for use in clinical diagnostic testing. However, their clinical utility and reliability are currently limited. Therefore, we performed a validation of a commercial AI tool (Moon) and a comprehensive reanalysis of previously collected clinical exome sequencing cases using an open-source variant prioritization tool (Exomiser) and the now-validated AI tool to test their feasibility in clinical diagnostics.MethodsA validation study of Moon was performed with 29 positive cases determined by previous manual analysis. After validation, reanalysis was performed on 80 previously manually analyzed nondiagnostic exome cases using Moon. Finally, a comparison between Moon and Exomiser was completed regarding their ability to identify previously completed positive cases and to identify new positive cases.ResultsMoon correctly selected the causal variant(s) in 97% of manually analyzed positive cases and identified 7 new positive cases. Exomiser correctly identified the causal gene in 85% of positive cases and agreed with Moon by ranking the new gene in its top 10 list 43% of the time.ConclusionThe use of AI in diagnostic laboratories greatly enhances exome sequencing analysis by reducing analysis time and increasing the diagnostic rate.     

An integrated multiomic approach as an excellent tool for the diagnosis of metabolic diseases: our first 3720 patients

To present our experience using a multiomic approach, which integrates genetic and biochemical testing as a first-line diagnostic tool for patients with inherited metabolic disorders (IMDs). A cohort of 3720 patients from 62 countries was tested using a panel including 206 genes with single nucleotide and copy number variant (SNV/CNV) detection, followed by semi-automatic variant filtering and reflex biochemical testing (25 assays). In 1389 patients (37%), a genetic diagnosis was achieved. Within this cohort, the highest diagnostic yield was obtained for patients from Asia (57.5%, mainly from Pakistan). Overall, 701 pathogenic/likely pathogenic unique SNVs and 40 CNVs were identified. In 620 patients, the result of the biochemical tests guided variant classification and reporting. Top five diagnosed diseases were: Gaucher disease, Niemann-Pick disease type A/B, phenylketonuria, mucopolysaccharidosis type I, and Wilson disease. We show that integrated genetic and biochemical testing facilitated the decision on clinical relevance of the variants and led to a high diagnostic yield (37%), which is comparable to exome/genome sequencing. More importantly, up to 43% of these patients (n = 610) could benefit from medical treatments (e.g., enzyme replacement therapy). This multiomic approach constitutes a unique and highly effective tool for the genetic diagnosis of IMDs.Subject terms: Metabolic disorders, Next-generation sequencing     

Panel-based genetic diagnostic testing for inherited eye diseases is highly accurate and reproducible,and more sensitive for variant detection,than exome sequencing

PurposeNext-generation sequencing–based methods are being adopted broadly for genetic diagnostic testing, but the performance characteristics of these techniques with regard to test accuracy and reproducibility have not been fully defined.MethodsWe developed a targeted enrichment and next-generation sequencing approach for genetic diagnostic testing of patients with inherited eye disorders, including inherited retinal degenerations, optic atrophy, and glaucoma. In preparation for providing this genetic eye disease (GEDi) test on a CLIA–certified basis, we performed experiments to measure the sensitivity, specificity, and reproducibility, as well as the clinical sensitivity, of the test.ResultsThe GEDi test is highly reproducible and accurate, with sensitivity and specificity of 97.9 and 100%, respectively, for single-nucleotide variant detection. The sensitivity for variant detection was notably better than the 88.3% achieved by whole-exome sequencing using the same metrics, because of better coverage of targeted genes in the GEDi test as compared with a commercially available exome capture set. Prospective testing of 192 patients with inherited retinal degenerations indicated that the clinical sensitivity of the GEDi test is high, with a diagnostic rate of 51%.ConclusionBased on quantified performance metrics, the data suggest that selective targeted enrichment is preferable to whole-exome sequencing for genetic diagnostic testing.Genet Med 17 4, 253–261.     

Implementation of fetal clinical exome sequencing: Comparing prospective and retrospective cohorts

PurposeWe compared the diagnostic yield of fetal clinical exome sequencing (fCES) in prospective and retrospective cohorts of pregnancies presenting with anomalies detected using ultrasound. We evaluated factors that led to a higher diagnostic efficiency, such as phenotypic category, clinical characterization, and variant analysis strategy.MethodsfCES was performed for 303 fetuses (183 ongoing and 120 ended pregnancies, in which chromosomal abnormalities had been excluded) using a trio/duo-based approach and a multistep variant analysis strategy.ResultsfCES identified the underlying genetic cause in 13% (24/183) of prospective and 29% (35/120) of retrospective cases. In both cohorts, recessive heterozygous compound genotypes were not rare, and trio and simplex variant analysis strategies were complementary to achieve the highest possible diagnostic rate. Limited prenatal phenotypic information led to interpretation challenges. In 2 prospective cases, in-depth analysis allowed expansion of the spectrum of prenatal presentations for genetic syndromes associated with the SLC17A5 and CHAMP1 genes.ConclusionfCES is diagnostically efficient in fetuses presenting with cerebral, skeletal, urinary, or multiple anomalies. The comparison between the 2 cohorts highlights the importance of providing detailed phenotypic information for better interpretation and prenatal reporting of genetic variants.     

Clinical and genetic spectrum of a large cohort of children with epilepsy in China

PurposeGenetic diagnosis for children suffering from epilepsy has important implications for treatment, prognosis, and development of precision medicine strategies.MethodsWe performed exome sequencing (ES) or targeted sequencing on 733 children with epilepsy onset within the first year of life. We subgrouped our patients based on the onset age of seizure into neonatal and before 1 year (1–12 months), to compare the clinical and genetic features.ResultsThe subgroups with different onset age of seizure showed different pathogenic variant spectrum, and the 1-year age group was more likely to have developmental delays than the neonate group (p = 0.000614). The diagnostic rate was 26.7% for targeted sequencing using a 2742-gene panel, and 42% for ES. We identified 12 genes, which covered 48.7% of diagnostic cases. Our data revealed that 41.9% of patients in the neonate group and 49.7% patients in the 1-year group had treatment options based on molecular diagnosis.ConclusionThe 12 most commonly implicated genes in this cohort and the genes with treatment options should be considered as part of the essential panel for early diagnosis of epilepsy onset, if large medical exome analyses or ES are not feasible as first-tier analysis. Genetic results are beginning to improve therapy by antiepileptic medication selections and precision medicine approaches.     

Phenotype-driven gene target definition in clinical genome-wide sequencing data interpretation

PurposeGenome-wide sequencing approaches are increasingly being used in place of disease gene panel sequencing approaches. Despite the well-recognized benefits of these approaches, they also carry with them an increased burden of analyzing overwhelmingly large gene targets and an increased possibility of detecting incidental findings.MethodsWe propose a novel approach for design of individualized phenotype gene panels using the set of signs and symptoms observed and selecting relevant genes on the basis of known phenotype–gene associations.ResultsWe used results of diagnostic exome sequencing in 405 cases submitted to our institution to show retrospectively that using the phenotype gene panel increases the sensitivity of masked exome analysis (increase from 25.4 to 29.7% in overall diagnostic yield). We also show that such a strategy enables the possibility of masked analysis of genome-wide sequencing data in patients with poorly defined and multifaceted clinical presentations. Ultimately, we show that this approach enables control over the incidental findings rate (0.25% in phenotype gene panels). Finally, we provide a Web tool for customized phenotype panel creation (available at http://www.kimg.eu/generator).ConclusionIn conclusion, we present a novel approach to a phenotype-driven diagnostic process of genome scale sequencing data that harnesses the sensitivity of these approaches while restricting the analysis to genes relevant to clinical presentation in patient.Genet Med 18 11, 1102–1110.     

Prenatal exome sequencing in 65 fetuses with abnormality of the corpus callosum: contribution to further diagnostic delineation

PurposeAbnormality of the corpus callosum (AbnCC) is etiologically a heterogeneous condition and the prognosis in prenatally diagnosed cases is difficult to predict. The purpose of our research was to establish the diagnostic yield using chromosomal microarray (CMA) and exome sequencing (ES) in cases with prenatally diagnosed isolated (iAbnCC) and nonisolated AbnCC (niAbnCC).MethodsCMA and prenatal trio ES (pES) were done on 65 fetuses with iAbnCC and niAbnCC. Only pathogenic gene variants known to be associated with AbnCC and/or intellectual disability were considered.ResultspES results were available within a median of 21.5 days (9–53 days). A pathogenic single-nucleotide variant (SNV) was identified in 12 cases (18%) and a pathogenic CNV was identified in 3 cases (4.5%). Thus, the genetic etiology was determined in 23% of cases. In all diagnosed cases, the results provided sufficient information regarding the neurodevelopmental prognosis and helped the parents to make an informed decision regarding the outcome of the pregnancy.ConclusionOur results show the significant diagnostic and prognostic contribution of CMA and pES in cases with prenatally diagnosed AbnCC. Further prospective cohort studies with long-term follow-up of the born children will be needed to provide accurate prenatal counseling after a negative pES result.     

CNVs cause autosomal recessive genetic diseases with or without involvement of SNV/indels

PurposeImproved resolution of molecular diagnostic technologies enabled detection of smaller sized exonic level copy-number variants (CNVs). The contribution of CNVs to autosomal recessive (AR) conditions may be better recognized using a large clinical cohort.MethodsWe retrospectively investigated the CNVs’ contribution to AR conditions in cases subjected to chromosomal microarray analysis (CMA, N = ~70,000) and/or clinical exome sequencing (ES, N = ~12,000) at Baylor Genetics; most had pediatric onset neurodevelopmental disorders.ResultsCNVs contributed to biallelic variations in 87 cases, including 81 singletons and three affected sibling pairs. Seventy cases had CNVs affecting both alleles, and 17 had a CNV and a single-nucleotide variant (SNV)/indel in trans. In total, 94.3% of AR-CNVs affected one gene; among these 41.4% were single-exon and 35.0% were multiexon partial-gene events. Sixty-nine percent of homozygous AR-CNVs were embedded in homozygous genomic intervals. Five cases had large deletions unmasking an SNV/indel on the intact allele for a recessive condition, resulting in multiple molecular diagnoses.ConclusionsAR-CNVs are often smaller in size, transmitted through generations, and underrecognized due to limitations in clinical CNV detection methods. Our findings from a large clinical cohort emphasized integrated CNV and SNV/indel analyses for precise clinical and molecular diagnosis especially in the context of genomic disorders.     

Diagnostic exome sequencing in early‐onset Parkinson's disease confirms VPS13C as a rare cause of autosomal‐recessive Parkinson's disease

Parkinson's disease (PD) is a genetically heterogeneous disorder and new putative disease genes are discovered constantly. Therefore, whole‐exome sequencing could be an efficient approach to genetic testing in PD. To evaluate its performance in early‐onset sporadic PD, we performed diagnostic exome sequencing in 80 individuals with manifestation of PD symptoms at age 40 or earlier and a negative family history of PD. Variants in validated and candidate disease genes and risk factors for PD and atypical Parkinson syndromes were annotated, followed by further analysis for selected variants. We detected pathogenic variants in Mendelian genes in 6.25% of cases and high‐impact risk factor variants in GBA in 5% of cases, resulting in overall maximum diagnostic yield of 11.25%. One individual was compound heterozygous for variants affecting canonical splice sites in VPS13C, confirming the causal role of protein‐truncating variants in this gene linked to autosomal‐recessive early‐onset PD. Despite the low diagnostic yield of exome sequencing in sporadic early‐onset PD, the confirmation of the recently discovered VPS13C gene highlights its advantage over using predefined gene panels.     

Assessing copy number from exome sequencing and exome array CGH based on CNV spectrum in a large clinical cohort

PurposeDetection of copy-number variation (CNV) is important for investigating many genetic disorders. Testing a large clinical cohort by array comparative genomic hybridization provides a deep perspective on the spectrum of pathogenic CNV. In this context, we describe a bioinformatics approach to extract CNV information from whole-exome sequencing and demonstrate its utility in clinical testing.MethodsExon-focused arrays and whole-genome chromosomal microarray analysis were used to test 14,228 and 14,000 individuals, respectively. Based on these results, we developed an algorithm to detect deletions/duplications in whole-exome sequencing data and a novel whole-exome array.ResultsIn the exon array cohort, we observed a positive detection rate of 2.4% (25 duplications, 318 deletions), of which 39% involved one or two exons. Chromosomal microarray analysis identified 3,345 CNVs affecting single genes (18%). We demonstrate that our whole-exome sequencing algorithm resolves CNVs of three or more exons.ConclusionThese results demonstrate the clinical utility of single-exon resolution in CNV assays. Our whole-exome sequencing algorithm approaches this resolution but is complemented by a whole-exome array to unambiguously identify intragenic CNVs and single-exon changes. These data illustrate the next advancements in CNV analysis through whole-exome sequencing and whole-exome array.Genet Med17 8, 623–629.