@article {774, title = {TBX6 missense variants expand the mutational spectrum in a non-Mendelian inheritance disease.}, journal = {Hum Mutat}, volume = {41}, year = {2020}, month = {2020 01}, pages = {182-195}, abstract = {

Congenital scoliosis (CS) is a birth defect with variable clinical and anatomical manifestations due to spinal malformation. The genetic etiology underlying about 10\% of CS cases in the Chinese population is compound inheritance by which the gene dosage is reduced below that of haploinsufficiency. In this genetic model, the trait manifests as a result of the combined effect of a rare variant and common pathogenic variant allele at a locus. From exome sequencing (ES) data of 523 patients in Asia and two patients in Texas, we identified six TBX6 gene-disruptive variants from 11 unrelated CS patients via ES and in vitro functional testing. The in trans mild hypomorphic allele was identified in 10 of the 11 subjects; as anticipated these 10 shared a similar spinal deformity of hemivertebrae. The remaining case has a homozygous variant in TBX6 (c.418C>T) and presents a more severe spinal deformity phenotype. We found decreased transcriptional activity and abnormal cellular localization as the molecular mechanisms for TBX6 missense loss-of-function alleles. Expanding the mutational spectrum of TBX6 pathogenic alleles enabled an increased molecular diagnostic detection rate, provided further evidence for the gene dosage-dependent genetic model underlying CS, and refined clinical classification.

}, keywords = {Alleles, Cell Line, Female, Gene Expression, Genes, Reporter, Genetic Association Studies, Genetic Predisposition to Disease, Genotype, Haplotypes, Humans, Inheritance Patterns, Male, Models, Molecular, Molecular Diagnostic Techniques, Mutation, Missense, Phenotype, Protein Conformation, Radiography, Sequence Analysis, DNA, Spine, Structure-Activity Relationship, T-Box Domain Proteins, Whole Exome Sequencing}, issn = {1098-1004}, doi = {10.1002/humu.23907}, author = {Chen, Weisheng and Lin, Jiachen and Wang, Lianlei and Li, Xiaoxin and Zhao, Sen and Liu, Jiaqi and Akdemir, Zeynep C and Zhao, Yanxue and Du, Renqian and Ye, Yongyu and Song, Xiaofei and Zhang, Yuanqiang and Yan, Zihui and Yang, Xinzhuang and Lin, Mao and Shen, Jianxiong and Wang, Shengru and Gao, Na and Yang, Ying and Liu, Ying and Li, Wenli and Liu, Jia and Zhang, Na and Yang, Xu and Xu, Yuan and Zhang, Jianguo and Delgado, Mauricio R and Posey, Jennifer E and Qiu, Guixing and Rios, Jonathan J and Liu, Pengfei and Wise, Carol A and Zhang, Feng and Wu, Zhihong and Lupski, James R and Wu, Nan} } @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 {185, title = {Absence of heterozygosity due to template switching during replicative rearrangements.}, journal = {Am J Hum Genet}, volume = {96}, year = {2015}, month = {2015 Apr 02}, pages = {555-64}, abstract = {

We investigated complex genomic rearrangements (CGRs) consisting of triplication copy-number variants (CNVs) that were accompanied by extended regions of copy-number-neutral absence of heterozygosity (AOH) in subjects with multiple congenital abnormalities. Molecular analyses provided observational evidence that in humans, post-zygotically generated CGRs can lead to regional uniparental disomy (UPD) due to template switches between homologs versus sister chromatids by using microhomology to prime DNA replication-a prediction of the replicative repair model, MMBIR. Our findings suggest that replication-based mechanisms might underlie the formation of diverse types of genomic alterations (CGRs and AOH) implicated in constitutional disorders.

}, keywords = {Base Sequence, DNA Copy Number Variations, DNA Repair, DNA Replication, Gene Rearrangement, Humans, In Situ Hybridization, Fluorescence, Loss of Heterozygosity, Models, Genetic, Molecular Sequence Data, Netherlands, Polymerase Chain Reaction, Polymorphism, Single Nucleotide, Sequence Analysis, DNA, Uniparental Disomy}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2015.01.021}, author = {Carvalho, Claudia M B and Pfundt, Rolph and King, Daniel A and Lindsay, Sarah J and Zuccherato, Luciana W and Macville, Merryn V E and Liu, Pengfei and Johnson, Diana and Stankiewicz, Pawel and Brown, Chester W and Shaw, Chad A and Hurles, Matthew E and Ira, Grzegorz and Hastings, P J and Brunner, Han G and Lupski, James R} } @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} }