@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 {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 {248, title = {De novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea.}, journal = {Am J Hum Genet}, volume = {94}, year = {2014}, month = {2014 May 01}, pages = {784-9}, abstract = {

Clinical whole-exome sequencing (WES) for identification of mutations leading to Mendelian disease has been offered to the medical community since 2011. Clinically undiagnosed neurological disorders are the most frequent basis for test referral, and currently, approximately 25\% of such cases are diagnosed at the molecular level. To date, there are approximately 4,000 "known" disease-associated loci, and many are associated with striking dysmorphic features, making genotype-phenotype correlations relatively straightforward. A significant fraction of cases, however, lack characteristic dysmorphism or clinical pathognomonic traits and are dependent upon molecular tests for definitive diagnoses. Further, many molecular diagnoses are guided by recent gene-disease association discoveries. Hence, there is a critical interplay between clinical testing and research leading to gene-disease association discovery. Here, we describe four probands, all of whom presented with hypotonia, intellectual disability, global developmental delay, and mildly dysmorphic facial features. Three of the four also had sleep apnea. Each was a simplex case without a remarkable family history. Using WES, we identified AHDC1 de novo truncating mutations that most likely cause this genetic syndrome.

}, keywords = {Child, Child, Preschool, DNA-Binding Proteins, Exome, Female, Humans, Infant, Intellectual Disability, Language Development Disorders, Male, Muscle Hypotonia, Mutation, Sleep Apnea Syndromes, Syndrome}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2014.04.006}, author = {Xia, Fan and Bainbridge, Matthew N and Tan, Tiong Yang and Wangler, Michael F and Scheuerle, Angela E and Zackai, Elaine H and Harr, Margaret H and Sutton, V Reid and Nalam, Roopa L and Zhu, Wenmiao and Nash, Margot and Ryan, Monique M and Yaplito-Lee, Joy and Hunter, Jill V and Deardorff, Matthew A and Penney, Samantha J and Beaudet, Arthur L and Plon, Sharon E and Boerwinkle, Eric A and Lupski, James R and Eng, Christine M and Muzny, Donna M and Yang, Yaping and Gibbs, Richard A} } @article {257, title = {Heterozygous de novo and inherited mutations in the smooth muscle actin (ACTG2) gene underlie megacystis-microcolon-intestinal hypoperistalsis syndrome.}, journal = {PLoS Genet}, volume = {10}, year = {2014}, month = {2014 Mar}, pages = {e1004258}, abstract = {

Megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) is a rare disorder of enteric smooth muscle function affecting the intestine and bladder. Patients with this severe phenotype are dependent on total parenteral nutrition and urinary catheterization. The cause of this syndrome has remained a mystery since Berdon{\textquoteright}s initial description in 1976. No genes have been clearly linked to MMIHS. We used whole-exome sequencing for gene discovery followed by targeted Sanger sequencing in a cohort of patients with MMIHS and intestinal pseudo-obstruction. We identified heterozygous ACTG2 missense variants in 15 unrelated subjects, ten being apparent de novo mutations. Ten unique variants were detected, of which six affected CpG dinucleotides and resulted in missense mutations at arginine residues, perhaps related to biased usage of CpG containing codons within actin genes. We also found some of the same heterozygous mutations that we observed as apparent de novo mutations in MMIHS segregating in families with intestinal pseudo-obstruction, suggesting that ACTG2 is responsible for a spectrum of smooth muscle disease. ACTG2 encodes γ2 enteric actin and is the first gene to be clearly associated with MMIHS, suggesting an important role for contractile proteins in enteric smooth muscle disease.

}, keywords = {Abnormalities, Multiple, Actins, Adolescent, Adult, Child, Child, Preschool, Colon, Exome, Female, Heterozygote, Humans, Intestinal Pseudo-Obstruction, Male, Muscle, Smooth, Mutation, Urinary Bladder}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1004258}, author = {Wangler, Michael F and Gonzaga-Jauregui, Claudia and Gambin, Tomasz and Penney, Samantha and Moss, Timothy and Chopra, Atul and Probst, Frank J and Xia, Fan and Yang, Yaping and Werlin, Steven and Eglite, Ieva and Kornejeva, Liene and Bacino, Carlos A and Baldridge, Dustin and Neul, Jeff and Lehman, Efrat Lev and Larson, Austin and Beuten, Joke and Muzny, Donna M and Jhangiani, Shalini and Gibbs, Richard A and Lupski, James R and Beaudet, Arthur} }