@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 {39, title = {Exome sequencing in mostly consanguineous Arab families with neurologic disease provides a high potential molecular diagnosis rate.}, journal = {BMC Med Genomics}, volume = {9}, year = {2016}, month = {2016 Jul 19}, pages = {42}, abstract = {

BACKGROUND: Neurodevelopment is orchestrated by a wide range of genes, and the genetic causes of neurodevelopmental disorders are thus heterogeneous. We applied whole exome sequencing (WES) for molecular diagnosis and in silico analysis to identify novel disease gene candidates in a cohort from Saudi Arabia with primarily Mendelian neurologic diseases.

METHODS: We performed WES in 31 mostly consanguineous Arab families and analyzed both single nucleotide and copy number variants (CNVs) from WES data. Interaction/expression network and pathway analyses, as well as paralog studies were utilized to investigate potential pathogenicity and disease association of novel candidate genes. Additional cases for candidate genes were identified through the clinical WES database at Baylor Miraca Genetics Laboratories and GeneMatcher.

RESULTS: We found known pathogenic or novel variants in known disease genes with phenotypic expansion in 6 families, disease-associated CNVs in 2 families, and 12 novel disease gene candidates in 11 families, including KIF5B, GRM7, FOXP4, MLLT1, and KDM2B. Overall, a potential molecular diagnosis was provided by variants in known disease genes in 17 families (54.8~\%) and by novel candidate disease genes in an additional 11 families, making the potential molecular diagnostic rate ~90~\%.

CONCLUSIONS: Molecular diagnostic rate from WES is improved by exome-predicted CNVs. Novel candidate disease gene discovery is facilitated by paralog studies and through the use of informatics tools and available databases to identify additional evidence for pathogenicity.

TRIAL REGISTRATION: Not applicable.

}, keywords = {Arabs, Cohort Studies, Consanguinity, Data Mining, Databases, Genetic, DNA Copy Number Variations, Exome, Female, High-Throughput Nucleotide Sequencing, Humans, Male, Molecular Diagnostic Techniques, Nervous System Diseases, Pedigree, Phenotype, Polymorphism, Single Nucleotide, Sequence Analysis, DNA}, issn = {1755-8794}, doi = {10.1186/s12920-016-0208-3}, author = {Charng, Wu-Lin and Karaca, Ender and Coban Akdemir, Zeynep and Gambin, Tomasz and Atik, Mehmed M and Gu, Shen and Posey, Jennifer E and Jhangiani, Shalini N and Muzny, Donna M and Doddapaneni, Harsha and Hu, Jianhong and Boerwinkle, Eric and Gibbs, Richard A and Rosenfeld, Jill A and Cui, Hong and Xia, Fan and Manickam, Kandamurugu and Yang, Yaping and Faqeih, Eissa A and Al Asmari, Ali and Saleh, Mohammed A M and El-Hattab, Ayman W 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} }