@article {750, title = {Exome sequencing reveals a novel variant in causing intracranial aneurysm in a Chinese family.}, journal = {J Neurointerv Surg}, volume = {12}, year = {2020}, month = {2020 Feb}, pages = {221-226}, abstract = {

BACKGROUND: Genetic risk factors play an important role in the pathogenesis of familial intracranial aneurysms (FIAs); however, the molecular mechanisms remain largely unknown.

OBJECTIVE: To investigate potential FIA-causing genetic variants by rare variant interrogation and a family-based genomics approach in a large family with an extensive multigenerational pedigree with FIAs.

METHOD: Exome sequencing (ES) was performed in a dominant likely family with intracranial aneurysms (IAs). Variants were analyzed by an in-house developed pipeline and prioritized using various filtering strategies, including population frequency, variant type, and predicted variant pathogenicity. Sanger sequencing was also performed to evaluate the segregation of the variants with the phenotype.

RESULTS: Based on the ES data obtained from five individuals from a family with 7/21 living members affected with IAs, a total of 14 variants were prioritized as candidate variants. Familial segregation analysis revealed that c.2519T>C (p.Leu840Pro) segregated in accordance with Mendelian expectations with the phenotype within the family-that is, present in all IA-affected cases and absent from all unaffected members of the second generation. This missense variant is absent from public databases (1000genome, ExAC, gnomAD, ESP5400), and has damaging predictions by bioinformatics tools (Gerp ++ score = 5.88, CADD score = 16.43, MutationTaster score = 1, LRT score = 0). In addition, 840Leu in NFX1 is robustly conserved in mammals and maps in a region before the RING-type zinc finger domain.

CONCLUSION: c.2519T>C (p.Leu840Pro) may contribute to the pathogenetics of a subset of FIAs.

}, keywords = {Adult, Asian Continental Ancestry Group, Computational Biology, Exome, Female, Genetic Variation, Humans, Intracranial Aneurysm, Male, Middle Aged, Pedigree, Phenotype, Repressor Proteins}, issn = {1759-8486}, doi = {10.1136/neurintsurg-2019-014900}, author = {Ding, Xinghuan and Zhao, Sen and Zhang, Qianqian and Yan, Zihui and Wang, Yang and Wu, Yong and Li, Xiaoxin and Liu, Jian and Niu, Yuchen and Zhang, Yisen and Zhang, Mingqi and Wang, Huizi and Zhang, Ying and Chen, Weisheng and Yang, Xin-Zhuang and Liu, Pengfei and Posey, Jennifer E and Lupski, James R and Wu, Zhihong and Yang, Xinjian and Wu, Nan and Wang, Kun} } @article {915, title = {Low-level parental somatic mosaic SNVs in exomes from a large cohort of trios with diverse suspected Mendelian conditions.}, journal = {Genet Med}, volume = {22}, year = {2020}, month = {2020 11}, pages = {1768-1776}, abstract = {

PURPOSE: The goal of this study was to assess the scale of low-level parental mosaicism in exome sequencing (ES) databases.

METHODS: We analyzed approximately 2000 family trio ES data sets from the Baylor-Hopkins Center for Mendelian Genomics (BHCMG) and Baylor Genetics (BG). Among apparent de novo single-nucleotide variants identified in the affected probands, we selected rare unique variants with variant allele fraction (VAF) between 30\% and 70\% in the probands and lower than 10\% in one of the parents.

RESULTS: Of 102 candidate mosaic variants validated using amplicon-based next-generation sequencing, droplet digital polymerase chain reaction, or blocker displacement amplification, 27 (26.4\%) were confirmed to be low- (VAF between 1\% and 10\%) or very low (VAF <1\%) level mosaic. Detection precision in parental samples with two or more alternate reads was 63.6\% (BHCMG) and 43.6\% (BG). In nine investigated individuals, we observed variability of mosaic ratios among blood, saliva, fibroblast, buccal, hair, and urine samples.

CONCLUSION: Our computational pipeline enables robust discrimination between true and false positive candidate mosaic variants and efficient detection of low-level mosaicism in ES samples. We confirm that the presence of two or more alternate reads in the parental sample is a reliable predictor of low-level parental somatic mosaicism.

}, keywords = {Exome, High-Throughput Nucleotide Sequencing, Humans, Mosaicism, Parents, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-020-0897-z}, author = {Gambin, Tomasz and Liu, Qian and Karolak, Justyna A and Grochowski, Christopher M and Xie, Nina G and Wu, Lucia R and Yan, Yan Helen and Cao, Ye and Coban Akdemir, Zeynep H and Wilson, Theresa A and Jhangiani, Shalini N and Chen, Ed and Eng, Christine M and Muzny, Donna and Posey, Jennifer E and Yang, Yaping and Zhang, David Y and Shaw, Chad and Liu, Pengfei and Lupski, James R and Stankiewicz, Pawe{\l}} } @article {515, title = {Clinical exome sequencing reveals locus heterogeneity and phenotypic variability of cohesinopathies.}, journal = {Genet Med}, volume = {21}, year = {2019}, month = {2019 03}, pages = {663-675}, abstract = {

PURPOSE: Defects in the cohesin pathway are associated with cohesinopathies, notably Cornelia de Lange syndrome (CdLS). We aimed to delineate pathogenic variants~in known and candidate cohesinopathy genes from a clinical exome perspective.

METHODS: We retrospectively studied patients referred for clinical exome sequencing (CES, N = 10,698). Patients with causative variants in novel or recently described cohesinopathy genes were enrolled for phenotypic characterization.

RESULTS: Pathogenic or likely pathogenic single-nucleotide and insertion/deletion variants (SNVs/indels) were identified in established disease genes including NIPBL (N = 5), SMC1A (N = 14), SMC3 (N = 4), RAD21 (N = 2), and HDAC8 (N = 8). The phenotypes in this genetically defined cohort skew towards the mild end of CdLS spectrum as compared with phenotype-driven cohorts. Candidate or recently reported cohesinopathy genes were supported by de novo SNVs/indels in STAG1 (N = 3), STAG2 (N = 5), PDS5A (N = 1), and WAPL (N = 1), and one inherited SNV in PDS5A. We also identified copy-number deletions affecting STAG1 (two de novo, one of unknown inheritance) and STAG2 (one of unknown inheritance). Patients with STAG1 and STAG2 variants presented with overlapping features yet without characteristic facial features of CdLS.

CONCLUSION: CES effectively identified disease-causing alleles at the mild end of the cohensinopathy spectrum and enabled characterization of candidate disease genes.

}, keywords = {Adolescent, Alleles, Antigens, Nuclear, Biological Variation, Population, Carrier Proteins, Cell Cycle Proteins, Child, Child, Preschool, Chromosomal Proteins, Non-Histone, Cohort Studies, De Lange Syndrome, Exome, Female, Gene Frequency, Genetic Heterogeneity, Humans, INDEL Mutation, Male, Mutation, Nuclear Proteins, Phenotype, Polymorphism, Single Nucleotide, Proto-Oncogene Proteins, Retrospective Studies, Whole Exome Sequencing}, issn = {1530-0366}, doi = {10.1038/s41436-018-0085-6}, author = {Yuan, Bo and Neira, Juanita and Pehlivan, Davut and Santiago-Sim, Teresa and Song, Xiaofei and Rosenfeld, Jill and Posey, Jennifer E and Patel, Vipulkumar and Jin, Weihong and Adam, Margaret P and Baple, Emma L and Dean, John and Fong, Chin-To and Hickey, Scott E and Hudgins, Louanne and Leon, Eyby and Madan-Khetarpal, Suneeta and Rawlins, Lettie and Rustad, Cecilie F and Stray-Pedersen, Asbj{\o}rg and Tveten, Kristian and Wenger, Olivia and Diaz, Jullianne and Jenkins, Laura and Martin, Laura and McGuire, Marianne and Pietryga, Marguerite and Ramsdell, Linda and Slattery, Leah and Abid, Farida and Bertuch, Alison A and Grange, Dorothy and Immken, LaDonna and Schaaf, Christian P and Van Esch, Hilde and Bi, Weimin and Cheung, Sau Wai and Breman, Amy M and Smith, Janice L and Shaw, Chad and Crosby, Andrew H and Eng, Christine and Yang, Yaping and Lupski, James R and Xiao, Rui and Liu, Pengfei} } @article {673, title = {Reanalysis of Clinical Exome Sequencing Data.}, journal = {N Engl J Med}, volume = {380}, year = {2019}, month = {2019 06 20}, pages = {2478-2480}, keywords = {Exome, Genetic Diseases, Inborn, Genetic Testing, Humans, Mutation, Phenotype, Sequence Analysis, DNA, Whole Exome Sequencing}, issn = {1533-4406}, doi = {10.1056/NEJMc1812033}, author = {Liu, Pengfei and Meng, Linyan and Normand, Elizabeth A and Xia, Fan and Song, Xiaofei and Ghazi, Andrew and Rosenfeld, Jill and Magoulas, Pilar L and Braxton, Alicia and Ward, Patricia and Dai, Hongzheng and Yuan, Bo and Bi, Weimin and Xiao, Rui and Wang, Xia and Chiang, Theodore and Vetrini, Francesco and He, Weimin and Cheng, Hanyin and Dong, Jie and Gijavanekar, Charul and Benke, Paul J and Bernstein, Jonathan A and Eble, Tanya and Eroglu, Yasemen and Erwin, Deanna and Escobar, Luis and Gibson, James B and Gripp, Karen and Kleppe, Soledad and Koenig, Mary K and Lewis, Andrea M and Natowicz, Marvin and Mancias, Pedro and Minor, LaKeesha and Scaglia, Fernando and Schaaf, Christian P and Streff, Haley and Vernon, Hilary and Uhles, Crescenda L and Zackai, Elaine H and Wu, Nan and Sutton, V Reid and Beaudet, Arthur L and Muzny, Donna and Gibbs, Richard A and Posey, Jennifer E and Lalani, Seema and Shaw, Chad and Eng, Christine M and Lupski, James R and Yang, Yaping} } @article {357, title = {Lessons learned from additional research analyses of unsolved clinical exome cases.}, journal = {Genome Med}, volume = {9}, year = {2017}, month = {2017 03 21}, pages = {26}, abstract = {

BACKGROUND: Given the rarity of most single-gene Mendelian disorders, concerted efforts of data exchange between clinical and scientific communities are critical to optimize molecular diagnosis and novel disease gene discovery.

METHODS: We designed and implemented protocols for the study of cases for which a plausible molecular diagnosis was not achieved in a clinical genomics diagnostic laboratory (i.e. unsolved clinical exomes). Such cases were recruited to a research laboratory for further analyses, in order to potentially: (1) accelerate novel disease gene discovery; (2) increase the molecular diagnostic yield of whole exome sequencing (WES); and (3) gain insight into the genetic mechanisms of disease. Pilot project data included 74 families, consisting mostly of parent-offspring trios. Analyses performed on a research basis employed both WES from additional family members and complementary bioinformatics approaches and protocols.

RESULTS: Analysis of all possible modes of Mendelian inheritance, focusing on both single nucleotide variants (SNV) and copy number variant (CNV) alleles, yielded a likely contributory variant in 36\% (27/74) of cases. If one includes candidate genes with variants identified within a single family, a potential contributory variant was identified in a total of ~51\% (38/74) of cases enrolled in this pilot study. The molecular diagnosis was achieved in 30/63 trios (47.6\%). Besides this, the analysis workflow yielded evidence for pathogenic variants in disease-associated genes in 4/6 singleton cases (66.6\%), 1/1 multiplex family involving three affected siblings, and 3/4 (75\%) quartet families. Both the analytical pipeline and the collaborative efforts between the diagnostic and research laboratories provided insights that allowed recent disease gene discoveries (PURA, TANGO2, EMC1, GNB5, ATAD3A, and MIPEP) and increased the number of novel genes, defined in this study as genes identified in more than one family (DHX30 and EBF3).

CONCLUSION: An efficient genomics pipeline in which clinical sequencing in a diagnostic laboratory is followed by the detailed reanalysis of unsolved cases in a research environment, supplemented with WES data from additional family members, and subject to adjuvant bioinformatics analyses including relaxed variant filtering parameters in informatics pipelines, can enhance the molecular diagnostic yield and provide mechanistic insights into Mendelian disorders. Implementing these approaches requires collaborative clinical molecular diagnostic and research efforts.

}, keywords = {Adenosine Triphosphatases, ATPases Associated with Diverse Cellular Activities, Computational Biology, DNA Copy Number Variations, DNA-Binding Proteins, Exome, Female, Genetic Diseases, Inborn, Genomics, GTP-Binding Protein beta Subunits, Humans, Male, Membrane Proteins, Metalloendopeptidases, Mitochondrial Proteins, Pilot Projects, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Transcription Factors}, issn = {1756-994X}, doi = {10.1186/s13073-017-0412-6}, author = {Eldomery, Mohammad K and Coban-Akdemir, Zeynep and Harel, Tamar and Rosenfeld, Jill A and Gambin, Tomasz and Stray-Pedersen, Asbj{\o}rg and K{\"u}ry, S{\'e}bastien and Mercier, Sandra and Lessel, Davor and Denecke, Jonas and Wiszniewski, Wojciech and Penney, Samantha and Liu, Pengfei and Bi, Weimin and Lalani, Seema R and Schaaf, Christian P and Wangler, Michael F and Bacino, Carlos A and Lewis, Richard Alan and Potocki, Lorraine and Graham, Brett H and Belmont, John W and Scaglia, Fernando and Orange, Jordan S and Jhangiani, Shalini N and Chiang, Theodore and Doddapaneni, Harsha and Hu, Jianhong and Muzny, Donna M and Xia, Fan and Beaudet, Arthur L and Boerwinkle, Eric and Eng, Christine M and Plon, Sharon E and Sutton, V Reid and Gibbs, Richard A and Posey, Jennifer E and Yang, Yaping and Lupski, James R} } @article {339, title = {Resolution of Disease Phenotypes Resulting from Multilocus Genomic Variation.}, journal = {N Engl J Med}, volume = {376}, year = {2017}, month = {2017 01 05}, pages = {21-31}, abstract = {

BACKGROUND: Whole-exome sequencing can provide insight into the relationship between observed clinical phenotypes and underlying genotypes.

METHODS: We conducted a retrospective analysis of data from a series of 7374 consecutive unrelated patients who had been referred to a clinical diagnostic laboratory for whole-exome sequencing; our goal was to determine the frequency and clinical characteristics of patients for whom more than one molecular diagnosis was reported. The phenotypic similarity between molecularly diagnosed pairs of diseases was calculated with the use of terms from the Human Phenotype Ontology.

RESULTS: A molecular diagnosis was rendered for 2076 of 7374 patients (28.2\%); among these patients, 101 (4.9\%) had diagnoses that involved two or more disease loci. We also analyzed parental samples, when available, and found that de novo variants accounted for 67.8\% (61 of 90) of pathogenic variants in autosomal dominant disease genes and 51.7\% (15 of 29) of pathogenic variants in X-linked disease genes; both variants were de novo in 44.7\% (17 of 38) of patients with two monoallelic variants. Causal copy-number variants were found in 12 patients (11.9\%) with multiple diagnoses. Phenotypic similarity scores were significantly lower among patients in whom the phenotype resulted from two distinct mendelian disorders that affected different organ systems (50 patients) than among patients with disorders that had overlapping phenotypic features (30 patients) (median score, 0.21 vs. 0.36; P=1.77{\texttimes}10).

CONCLUSIONS: In our study, we found multiple molecular diagnoses in 4.9\% of cases in which whole-exome sequencing was informative. Our results show that structured clinical ontologies can be used to determine the degree of overlap between two mendelian diseases in the same patient; the diseases can be distinct or overlapping. Distinct disease phenotypes affect different organ systems, whereas overlapping disease phenotypes are more likely to be caused by two genes encoding proteins that interact within the same pathway. (Funded by the National Institutes of Health and the Ting Tsung and Wei Fong Chao Foundation.).

}, keywords = {Exome, Genetic Diseases, Inborn, Genetic Variation, Genotyping Techniques, High-Throughput Nucleotide Sequencing, Humans, Phenotype, Retrospective Studies, Sequence Analysis, DNA}, issn = {1533-4406}, doi = {10.1056/NEJMoa1516767}, author = {Posey, Jennifer E and Harel, Tamar and Liu, Pengfei and Rosenfeld, Jill A and James, Regis A and Coban Akdemir, Zeynep H and Walkiewicz, Magdalena and Bi, Weimin and Xiao, Rui and Ding, Yan and Xia, Fan and Beaudet, Arthur L and Muzny, Donna M and Gibbs, Richard A and Boerwinkle, Eric and Eng, Christine M and Sutton, V Reid and Shaw, Chad A and Plon, Sharon E and Yang, Yaping and Lupski, James R} } @article {540, title = {Use of Exome Sequencing for Infants in Intensive Care Units: Ascertainment of Severe Single-Gene Disorders and Effect on Medical Management.}, journal = {JAMA Pediatr}, volume = {171}, year = {2017}, month = {2017 12 04}, pages = {e173438}, abstract = {

Importance: While congenital malformations and genetic diseases are a leading cause of early infant death, to our knowledge, the contribution of single-gene disorders in this group is undetermined.

Objective: To determine the diagnostic yield and use of clinical exome sequencing in critically ill infants.

Design, Setting, and Participants: Clinical exome sequencing was performed for 278 unrelated infants within the first 100 days of life who were admitted to Texas Children{\textquoteright}s Hospital in Houston, Texas, during a 5-year period between December 2011 and January 2017. Exome sequencing types included proband exome, trio exome, and critical trio exome, a rapid genomic assay for seriously ill infants.

Main Outcomes and Measures: Indications for testing, diagnostic yield of clinical exome sequencing, turnaround time, molecular findings, patient age at diagnosis, and effect on medical management among a group of critically ill infants who were suspected to have genetic disorders.

Results: The mean (SEM) age for infants participating in the study was 28.5 (1.7) days; of these, the mean (SEM) age was 29.0 (2.2) days for infants undergoing proband exome sequencing, 31.5 (3.9) days for trio exome, and 22.7 (3.9) days for critical trio exome. Clinical indications for exome sequencing included a range of medical concerns. Overall, a molecular diagnosis was achieved in 102 infants (36.7\%) by clinical exome sequencing, with relatively low yield for cardiovascular abnormalities. The diagnosis affected medical management for 53 infants (52.0\%) and had a substantial effect on informed redirection of care, initiation of new subspecialist care, medication/dietary modifications, and furthering life-saving procedures in select patients. Critical trio exome sequencing revealed a molecular diagnosis in 32 of 63 infants (50.8\%) at a mean (SEM) of 33.1 (5.6) days of life with a mean (SEM) turnaround time of 13.0 (0.4) days. Clinical care was altered by the diagnosis in 23 of 32 patients (71.9\%). The diagnostic yield, patient age at diagnosis, and medical effect in the group that underwent critical trio exome sequencing were significantly different compared with the group who underwent regular exome testing. For deceased infants (n = 81), genetic disorders were molecularly diagnosed in 39 (48.1\%) by exome sequencing, with implications for recurrence risk counseling.

Conclusions and Relevance: Exome sequencing is a powerful tool for the diagnostic evaluation of critically ill infants with suspected monogenic disorders in the neonatal and pediatric intensive care units and its use has a notable effect on clinical decision making.

}, keywords = {Adult, Critical Care, Disease Management, Exome, Genetic Counseling, Genetic Diseases, Inborn, Humans, Infant, Infant Care, Infant, Newborn, Intensive Care Units, Pediatric, Length of Stay, Retrospective Studies, Texas, Whole Exome Sequencing}, issn = {2168-6211}, doi = {10.1001/jamapediatrics.2017.3438}, author = {Meng, Linyan and Pammi, Mohan and Saronwala, Anirudh and Magoulas, Pilar and Ghazi, Andrew Ray and Vetrini, Francesco and Zhang, Jing and He, Weimin and Dharmadhikari, Avinash V and Qu, Chunjing and Ward, Patricia and Braxton, Alicia and Narayanan, Swetha and Ge, Xiaoyan and Tokita, Mari J and Santiago-Sim, Teresa and Dai, Hongzheng and Chiang, Theodore and Smith, Hadley and Azamian, Mahshid S and Robak, Laurie and Bostwick, Bret L and Schaaf, Christian P and Potocki, Lorraine and Scaglia, Fernando and Bacino, Carlos A and Hanchard, Neil A and Wangler, Michael F and Scott, Daryl and Brown, Chester and Hu, Jianhong and Belmont, John W and Burrage, Lindsay C and Graham, Brett H and Sutton, Vernon Reid and Craigen, William J and Plon, Sharon E and Lupski, James R and Beaudet, Arthur L and Gibbs, Richard A and Muzny, Donna M and Miller, Marcus J and Wang, Xia and Leduc, Magalie S and Xiao, Rui and Liu, Pengfei and Shaw, Chad and Walkiewicz, Magdalena and Bi, Weimin and Xia, Fan and Lee, Brendan and Eng, Christine M and Yang, Yaping and Lalani, Seema R} } @article {90, title = {Recurrent Muscle Weakness with Rhabdomyolysis, Metabolic Crises, and Cardiac Arrhythmia Due to Bi-allelic TANGO2 Mutations.}, journal = {Am J Hum Genet}, volume = {98}, year = {2016}, month = {2016 Feb 04}, pages = {347-57}, abstract = {

The underlying genetic etiology of rhabdomyolysis remains elusive in a significant fraction of individuals presenting with recurrent metabolic crises and muscle weakness. Using exome sequencing, we identified bi-allelic mutations in TANGO2 encoding transport and Golgi organization 2 homolog (Drosophila) in 12 subjects with episodic rhabdomyolysis, hypoglycemia, hyperammonemia, and susceptibility to life-threatening cardiac tachyarrhythmias. A recurrent homozygous c.460G>A (p.Gly154Arg) mutation was found in four unrelated individuals of Hispanic/Latino origin, and a homozygous \~{}34 kb deletion affecting exons 3-9 was observed in two families of European ancestry. One individual of mixed Hispanic/European descent was found to be compound heterozygous for c.460G>A (p.Gly154Arg) and the deletion of exons 3-9. Additionally, a homozygous exons 4-6 deletion was identified in a consanguineous Middle Eastern Arab family. No homozygotes have been reported for these changes in control databases. Fibroblasts derived from a subject with the recurrent c.460G>A (p.Gly154Arg) mutation showed evidence of increased endoplasmic reticulum stress and a reduction in Golgi volume density in comparison to control. Our results show that the c.460G>A (p.Gly154Arg) mutation and the exons 3-9 heterozygous deletion in TANGO2 are recurrent pathogenic alleles present in the Latino/Hispanic and European populations, respectively, causing considerable morbidity in the homozygotes in these populations.

}, keywords = {Alleles, Arabs, Arrhythmias, Cardiac, Base Sequence, Child, Child, Preschool, Endoplasmic Reticulum Stress, European Continental Ancestry Group, Exome, Exons, Female, Gene Deletion, Golgi Apparatus, Hispanic Americans, Homozygote, Humans, Infant, Male, Molecular Sequence Data, Muscle Weakness, Pedigree, Rhabdomyolysis}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.12.008}, author = {Lalani, Seema R and Liu, Pengfei and Rosenfeld, Jill A and Watkin, Levi B and Chiang, Theodore and Leduc, Magalie S and Zhu, Wenmiao and Ding, Yan and Pan, Shujuan and Vetrini, Francesco and Miyake, Christina Y and Shinawi, Marwan and Gambin, Tomasz and Eldomery, Mohammad K and Akdemir, Zeynep Hande Coban and Emrick, Lisa and Wilnai, Yael and Schelley, Susan and Koenig, Mary Kay and Memon, Nada and Farach, Laura S and Coe, Bradley P and Azamian, Mahshid and Hernandez, Patricia and Zapata, Gladys and Jhangiani, Shalini N and Muzny, Donna M and Lotze, Timothy and Clark, Gary and Wilfong, Angus and Northrup, Hope and Adesina, Adekunle and Bacino, Carlos A and Scaglia, Fernando and Bonnen, Penelope E and Crosson, Jane and Duis, Jessica and Maegawa, Gustavo H B and Coman, David and Inwood, Anita and McGill, Jim and Boerwinkle, Eric and Graham, Brett and Beaudet, Art and Eng, Christine M and Hanchard, Neil A and Xia, Fan and Orange, Jordan S and Gibbs, Richard A and Lupski, James R and Yang, Yaping} } @article {217, title = {Molecular findings among patients referred for clinical whole-exome sequencing.}, journal = {JAMA}, volume = {312}, year = {2014}, month = {2014 Nov 12}, pages = {1870-9}, abstract = {

IMPORTANCE: Clinical whole-exome sequencing is increasingly used for diagnostic evaluation of patients with suspected genetic disorders.

OBJECTIVE: To perform clinical whole-exome sequencing and report (1) the rate of molecular diagnosis among phenotypic groups, (2) the spectrum of genetic alterations contributing to disease, and (3) the prevalence of medically actionable incidental findings such as FBN1 mutations causing Marfan syndrome.

DESIGN, SETTING, AND PATIENTS: Observational study of 2000 consecutive patients with clinical whole-exome sequencing analyzed between June 2012 and August 2014. Whole-exome sequencing tests were performed at a clinical genetics laboratory in the United States. Results were reported by clinical molecular geneticists certified by the American Board of Medical Genetics and Genomics. Tests were ordered by the patient{\textquoteright}s physician. The patients were primarily pediatric (1756 [88\%]; mean age, 6 years; 888 females [44\%], 1101 males [55\%], and 11 fetuses [1\% gender unknown]), demonstrating diverse clinical manifestations most often including nervous system dysfunction such as developmental delay.

MAIN OUTCOMES AND MEASURES: Whole-exome sequencing diagnosis rate overall and by phenotypic category, mode of inheritance, spectrum of genetic events, and reporting of incidental findings.

RESULTS: A molecular diagnosis was reported for 504 patients (25.2\%) with 58\% of the diagnostic mutations not previously reported. Molecular diagnosis rates for each phenotypic category were 143/526 (27.2\%; 95\% CI, 23.5\%-31.2\%) for the neurological group, 282/1147 (24.6\%; 95\% CI, 22.1\%-27.2\%) for the neurological plus other organ systems group, 30/83 (36.1\%; 95\% CI, 26.1\%-47.5\%) for the specific neurological group, and 49/244 (20.1\%; 95\% CI, 15.6\%-25.8\%) for the nonneurological group. The Mendelian disease patterns of the 527 molecular diagnoses included 280 (53.1\%) autosomal dominant, 181 (34.3\%) autosomal recessive (including 5 with uniparental disomy), 65 (12.3\%) X-linked, and 1 (0.2\%) mitochondrial. Of 504 patients with a molecular diagnosis, 23 (4.6\%) had blended phenotypes resulting from 2 single gene defects. About 30\% of the positive cases harbored mutations in disease genes reported since 2011. There were 95 medically actionable incidental findings in genes unrelated to the phenotype but with immediate implications for management in 92 patients (4.6\%), including 59 patients (3\%) with mutations in genes recommended for reporting by the American College of Medical Genetics and Genomics.

CONCLUSIONS AND RELEVANCE: Whole-exome sequencing provided a potential molecular diagnosis for 25\% of a large cohort of patients referred for evaluation of suspected genetic conditions, including detection of rare genetic events and new mutations contributing to disease. The yield of whole-exome sequencing may offer advantages over traditional molecular diagnostic approaches in certain patients.

}, keywords = {Adolescent, Adult, Child, Child, Preschool, Exome, Female, Fetus, Genetic Diseases, Inborn, Genetic Testing, Genomics, Humans, Incidental Findings, Infant, Infant, Newborn, Male, Molecular Diagnostic Techniques, Mutation, Phenotype, Referral and Consultation, Sequence Analysis, DNA}, issn = {1538-3598}, doi = {10.1001/jama.2014.14601}, author = {Yang, Yaping and Muzny, Donna M and Xia, Fan and Niu, Zhiyv and Person, Richard and Ding, Yan and Ward, Patricia and Braxton, Alicia and Wang, Min and Buhay, Christian and Veeraraghavan, Narayanan and Hawes, Alicia and Chiang, Theodore and Leduc, Magalie and Beuten, Joke and Zhang, Jing and He, Weimin and Scull, Jennifer and Willis, Alecia and Landsverk, Megan and Craigen, William J and Bekheirnia, Mir Reza and Stray-Pedersen, Asbjorg and Liu, Pengfei and Wen, Shu and Alcaraz, Wendy and Cui, Hong and Walkiewicz, Magdalena and Reid, Jeffrey and Bainbridge, Matthew and Patel, Ankita and Boerwinkle, Eric and Beaudet, Arthur L and Lupski, James R and Plon, Sharon E and Gibbs, Richard A and Eng, Christine M} }