CC BY-NC-ND 4.0 · Laryngorhinootologie 2019; 98(S 01): S32-S81
DOI: 10.1055/a-0803-6149
Referat
Eigentümer und Copyright ©Georg Thieme Verlag KG 2019

A Big Data Perspective on the Genomics of Hearing Loss

Article in several languages: deutsch | English
Barbara Vona
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
,
Marcus Müller
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
,
Saskia Dofek
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
,
Martin Holderried
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
,
Hubert Löwenheim
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
,
Anke Tropitzsch
1   Klinik für Hals-, Nasen- und Ohrenheilkunde, Eberhard Karls Universität, Universitätsklinik Tübingen
› Author Affiliations
Further Information

Publication History

Publication Date:
03 April 2019 (online)

Abstract

The completion of the human genome, the most fundamental example of big data in science and medicine, is the remarkable product of multidisciplinary collaboration and is regarded as one of the largest and most successful undertakings in human history. Unravelling the human genome means not only identifying the sequence of its more than 3.2 billion nucleotide bases, but also understanding disease-associated variations and applying this knowledge to patient-tailored precision medicine approaches. Genomics has moved at a remarkable pace, with much of the propelling forces behind this credited to technological developments in sequencing, computing, and bioinformatics, that have given rise to the term “big genomics data.” The analysis of genetics data in a disease context involves the use of several big data resources that take the form of clinical genetics data repositories, in silico prediction tools, and allele frequency databases. These exceptional developments have cultivated high-throughput sequencing technologies that are capable of producing affordable high-quality data ranging from targeted gene panels to exomes and genomes. These new advancements have revolutionized the diagnostic paradigm of hereditary diseases including genetic hearing loss.Dissecting hereditary hearing loss is exceptionally challenging due to extensive genetic and clinical heterogeneity. There are presently over 150 genes involved in non-syndromic and common syndromic forms of hearing loss. The mutational spectrum of a single hearing loss associated-gene can have several tens to hundreds of pathogenic variants. Moreover, variant interpretation of novel variants can pose a challenge when conflicting information is deposited in valuable databases. Harnessing the power that comes from detailed and structured phenotypic information has proven promising for some forms of hearing loss, but may not be possible for all genetic forms due to highly variable clinical presentations. New knowledge in both diagnostic and scientific realms continues to rapidly accumulate. This overwhelming amount of information represents an increasing challenge for medical specialists. As a result, specialist medical care may evolve to take on new tasks and facilitate the interface between the human genetic diagnostic laboratory and the patient. These tasks include genetic counselling and the inclusion of genetics results in patient care.This overview is intended to serve as a reference to otolaryngologists who wish to gain an introduction to the molecular genetics of hearing loss. Key concepts of molecular genetic diagnostics will be presented. The complex processes underlying the identification and interpretation of genetic variants in particular would be inconceivable without the enormous amount of data available. In this respect, "big data" is an indispensable prerequisite for filtering genetic data in specific individual cases and making it clear and useful, especially for clinicians in contact with patients.

 
  • Literatur

  • 1 Lek M, Karczewski KJ, Minikel EV. et al. Analysis of protein-coding genetic variation in 60,706 humans. Nature 2016; 536: 285-291
  • 2 Zarrei M, MacDonald JR, Merico D. et al. A copy number variation map of the human genome. Nat Rev Genet 2015; 16: 172-183
  • 3 Xue Y, Chen Y, Ayub Q. et al. Deleterious- and disease-allele prevalence in healthy individuals: insights from current predictions, mutation databases, and population-scale resequencing. Am J Hum Genet 2012; 91: 1022-1032
  • 4 Sudmant PH, Rausch T, Gardner EJ. et al. An integrated map of structural variation in 2,504 human genomes. Nature 2015; 526: 75-81
  • 5 Narasimhan VM, Hunt KA, Mason D. et al. Health and population effects of rare gene knockouts in adult humans with related parents. Science 2016; 352: 474-477
  • 6 Narasimhan VM, Xue Y, Tyler-Smith C. Human Knockout Carriers: Dead, Diseased, Healthy, or Improved?. Trends Mol Med 2016; 22: 341-351
  • 7 Consortium UK, Walter K, Min JL. et al. The UK10K project identifies rare variants in health and disease. Nature 2015; 526: 82-90
  • 8 Cassa CA, Tong MY, Jordan DM. Large Numbers of Genetic Variants Considered to be Pathogenic are Common in Asymptomatic Individuals. Hum Mutat 2013; 34: 1216-1220
  • 9 Sulem P, Helgason H, Oddson A. et al. Identification of a large set of rare complete human knockouts. Nat Genet 2015; 47: 448-452
  • 10 Dahm R. Discovering DNA: Friedrich Miescher and the early years of nucleic acid research. Hum Genet 2008; 122: 565-581
  • 11 Maderspacher F. Rags before the riches: Friedrich Miescher and the discovery of DNA. Current Biology 2004; 14: R608-R608
  • 12 Avery OT, MacLeod CM, McCarty M. Studies on the chemical nature of the substance inducing transformation of pneumococcal types: Induction of transformation by a desoxyribonucleic acid fraction isolated from Pneumococcus Type III. J Exp Med 1944; 79: 137-158
  • 13 Watson JD, Crick FH. Molecular structure of nucleic acids; a structure for deoxyribose nucleic acid. Nature 1953; 171: 737-738
  • 14 Zallen DT. Despite Franklin's work, Wilkins earned his Nobel. Nature 2003; 425: 15
  • 15 Efstratiadis A, Kafatos FC, Maniatis T. The primary structure of rabbit beta-globin mRNA as determined from cloned DNA. Cell 1977; 10: 571-585
  • 16 Shendure J, Balasubramanian S, Church GM. et al. DNA sequencing at 40: past, present and future. Nature 2017; 550: 345-353
  • 17 Sanger F, Nicklen S, Coulson AR. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 1977; 74: 5463-5467
  • 18 Saiki RK, Scharf S, Faloona F. et al. Enzymatic Amplification of Beta-Globin Genomic Sequences and Restriction Site Analysis for Diagnosis of Sickle-Cell Anemia. Science 1985; 230: 1350-1354
  • 19 Rose EA. Applications of the polymerase chain reaction to genome analysis. FASEB J 1991; 5: 46-54
  • 20 Dickman S. West-Germany Voices Objections to European Genome Project. Nature 1988; 336: 416-416
  • 21 Collins FS, Morgan M, Patrinos A. The Human Genome Project: lessons from large-scale biology. Science 2003; 300: 286-290
  • 22 Murray JC, Buetow KH, Weber JL. et al. A comprehensive human linkage map with centimorgan density. Cooperative Human Linkage Center (CHLC). Science 1994; 265: 2049-2054
  • 23 Fleischmann RD, Adams MD, White O. et al. Whole-genome random sequencing and assembly of Haemophilus influenzae Rd. Science 1995; 269: 496-512
  • 24 Dunham I, Shimizu N, Roe BA. et al. The DNA sequence of human chromosome 22. Nature 1999; 402: 489-495
  • 25 Adams MD, Celniker SE, Holt RA. et al. The genome sequence of Drosophila melanogaster. Science 2000; 287: 2185-2195
  • 26 Bier E. Drosophila, the golden bug, emerges as a tool for human genetics. Nat Rev Genet 2005; 6: 9-23
  • 27 Shendure J, Porreca GJ, Reppas NB. et al. Accurate multiplex polony sequencing of an evolved bacterial genome. Science 2005; 309: 1728-1732
  • 28 [Anonymous]. Method of the year. Nat Methods 2008; 5: 1
  • 29 Sevilla G. New GUINNESS WORLD RECORDS™ Title Set for Fastest Genetic Diagnosis. In. Rady Children's Hospital San Diego; 2018
  • 30 Vence T. $1,000 Genome at Last? In, The Scientist 2014
  • 31 Shendure J, Ji H. Next-generation DNA sequencing. Nat Biotechnol 2008; 26: 1135-1145
  • 32 Maxam AM, Gilbert W. A new method for sequencing DNA. Proc Natl Acad Sci, U S A 1977; 74: 560-564
  • 33 Illumina. An Introduction to Next-Generation Sequencing Technology. In: Illumina, Inc.; 2017
  • 34 Mardis ER. A decade's perspective on DNA sequencing technology. Nature 2011; 470: 198-203
  • 35 [Anonymous]. Illumina Introduces the NovaSeq Series—a New Architecture Designed to Usher in the $100 Genome. In: Business Wire 2017
  • 36 [Anonymous]. Genes and Human Disease. In: World Health Organization. 2018;
  • 37 Davies SC. Annual Report of the Chief Medical Officer 2016. In, Generation Genome 2017
  • 38 Morton CC, Nance WE. Newborn hearing screening – a silent revolution. N Engl J Med 2006; 354: 2151-2164
  • 39 Morton NE, Shields DC, Collins A. Genetic epidemiology of complex phenotypes. Ann Hum Genet 1991; 55: 301-314
  • 40 Sosnay PR, Siklosi KR, Van Goor F. et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet 2013; 45: 1160-1167
  • 41 Van Camp G, Smith RJH. Hereditary Hearing Loss Homepage. In: Shearer AE, Sommen M eds 2018;
  • 42 Shearer AE, Eppsteiner RW, Booth KT. et al. Utilizing ethnic-specific differences in minor allele frequency to recategorize reported pathogenic deafness variants. Am J Hum Genet 2014; 95: 445-453
  • 43 Stenson PD, Mort M, Ball EV. et al. The Human Gene Mutation Database: towards a comprehensive repository of inherited mutation data for medical research, genetic diagnosis and next-generation sequencing studies. Hum Genet 2017; 136: 665-677
  • 44 Bitner-Glindzicz M. Hereditary deafness and phenotyping in humans. Br Med Bull 2002; 63: 73-94
  • 45 Löwenheim H. [Zukunft der Hördiagnostik] [Article in German]. Zeitschrift für Audiologie Audiological Acoustics 2014; 20: 62-65
  • 46 Bartsch O, Vatter A, Zechner U. et al. GJB2 mutations and genotype-phenotype correlation in 335 patients from germany with nonsyndromic sensorineural hearing loss: evidence for additional recessive mutations not detected by current methods. Audiol Neurootol 2010; 15: 375-382
  • 47 Tropitzsch A, Friese N, Michels L. et al. Next-generation Sequencing in der Diagnostik der genetischen Schwerhörigkeit. 30 Wissenschaftliche Jahrestagung der Deutschen Gesellschaft für Phoniatrie und Pädaudiometrie. 2013. Bochum, Germany:
  • 48 Mahdieh N, Rabbani B. Statistical study of 35delG mutation of GJB2 gene: a meta-analysis of carrier frequency. Int J Audiol 2009; 48: 363-370
  • 49 Shearer AE, Black-Ziegelbein EA, Hildebrand MS. et al. Advancing genetic testing for deafness with genomic technology. J Med Genet 2013; 50: 627-634
  • 50 Shearer AE, Smith RJ. Massively Parallel Sequencing for Genetic Diagnosis of Hearing Loss: The New Standard of Care. Otolaryngol Head Neck Surg 2015; 153: 175-182
  • 51 Sie AS, Prins JB, van Zelst-Stams WA. et al. Patient experiences with gene panels based on exome sequencing in clinical diagnostics: High acceptance and low distress. Clin Genet 2015; 87: 319-326
  • 52 Sheppard S, Biswas S, Li MH et al. Utility and limitations of exome sequencing as a genetic diagnostic tool for children with hearing loss. Genet Med 2018 [Epub ahead of print]
  • 53 Guan Q, Balciuniene J, Cao K et al. AUDIOME: a tiered exome sequencing-based comprehensive gene panel for the diagnosis of heterogeneous nonsyndromic sensorineural hearing loss. Genet Med 2018 [Epub ahead of print]
  • 54 Zazo Seco C, Wesdorp M, Feenstra I. et al. The diagnostic yield of whole-exome sequencing targeting a gene panel for hearing impairment in The Netherlands. Eur J Hum Genet 2017; 25: 308-314
  • 55 Kalia SS, Adelman K, Bale SJ. et al. Recommendations for reporting of secondary findings in clinical exome and genome sequencing, 2016 update (ACMG SF v2.0): a policy statement of the American College of Medical Genetics and Genomics. Genet Med 2017; 19: 249-255
  • 56 [Anonymous]. [Opinion of the German Society for Human Genetics on additional genetic findings in diagnostics and Research] [Article in German]. In, Guidelines and Statements of the German Society for Human Genetics 2013;
  • 57 Bowl MR, Simon MM, Ingham NJ. et al. A large scale hearing loss screen reveals an extensive unexplored genetic landscape for auditory dysfunction. Nat Commun 2017; 8: 886
  • 58 Sommen M, Schrauwen I, Vandeweyer G. et al. DNA Diagnostics of Hereditary Hearing Loss: A Targeted Resequencing Approach Combined with a Mutation Classification System. Hum Mutat 2016; 37: 812-819
  • 59 Vona B, Muller T, Nanda I. et al. Targeted next-generation sequencing of deafness genes in hearing-impaired individuals uncovers informative mutations. Genet Med 2014; 16: 945-953
  • 60 Yan D, Tekin D, Bademci G. et al. Spectrum of DNA variants for non-syndromic deafness in a large cohort from multiple continents. Hum Genet 2016; 135: 953-961
  • 61 Baux D, Vache C, Blanchet C. et al. Combined genetic approaches yield a 48% diagnostic rate in a large cohort of French hearing-impaired patients. Sci Rep 2017; 7: 16783
  • 62 Sloan-Heggen CM, Bierer AO, Shearer AE. et al. Comprehensive genetic testing in the clinical evaluation of 1119 patients with hearing loss. Hum Genet 2016; 135: 441-450
  • 63 Alkowari MK, Vozzi D, Bhagat S. et al. Targeted sequencing identifies novel variants involved in autosomal recessive hereditary hearing loss in Qatari families. Mutat Res 2017; 800-802: 29-36
  • 64 Hernandez AL, Cox S, Kothiyal P. et al. The Otochip sequencing array for hearing loss and Usher syndrome. International Symposium on Usher Syndrome and Related Diseases 2010. Spain: Valencia;
  • 65 Shearer AE, Kolbe DL, Azaiez H. et al. Copy number variants are a common cause of non-syndromic hearing loss. Genome Med 2014; 6: 37
  • 66 Moteki H, Azaiez H, Sloan-Heggen CM. et al. Detection and Confirmation of Deafness-Causing Copy Number Variations in the STRC Gene by Massively Parallel Sequencing and Comparative Genomic Hybridization. Ann Otol Rhinol Laryngol 2016; 125: 918-923
  • 67 Vona B, Hofrichter MAH, Neuner C. et al. DFNB16 is a frequent cause of congenital hearing impairment: implementation of STRC mutation analysis in routine diagnostics. Clinical Genetics 2015; 87: 49-55
  • 68 Plevova P, Paprskarova M, Tvrda P. et al. STRC Deletion is a Frequent Cause of Slight to Moderate Congenital Hearing Impairment in the Czech Republic. Otology & Neurotology 2017; 38: E393-E400
  • 69 Francey LJ, Conlin LK, Kadesch HE. et al. Genome-wide SNP genotyping identifies the Stereocilin (STRC) gene as a major contributor to pediatric bilateral sensorineural hearing impairment. American Journal of Medical Genetics Part A 2012; 158a: 298-308
  • 70 Amr SS, Murphy E, Duffy E. et al. Allele-Specific Droplet Digital PCR Combined with a Next-Generation Sequencing-Based Algorithm for Diagnostic Copy Number Analysis in Genes with High Homology: Proof of Concept Using Stereocilin. Clinical Chemistry 2018; 64: 705-714
  • 71 Ren C, Liu F, Ouyang ZY. et al. Functional annotation of structural ncRNAs within enhancer RNAs in the human genome: Implications for human disease. Scientific Reports 2017; 7: 15518
  • 72 Nakano Y, Kelly MC, Rehman AU. et al. Defects in the Alternative Splicing-Dependent Regulation of REST Cause Deafness. Cell 2018; 174: 536-548 e521
  • 73 Khan AO, Becirovic E, Betz C. et al. A deep intronic CLRN1 (USH3A) founder mutation generates an aberrant exon and underlies severe Usher syndrome on the Arabian Peninsula. Sci Rep 2017; 7: 1411
  • 74 Frebourg T. The challenge for the next generation of medical geneticists. Hum Mutat 2014; 35: 909-911
  • 75 Stelzer G, Rosen N, Plaschkes I. et al. The GeneCards Suite: From Gene Data Mining to Disease Genome Sequence Analyses. Curr Protoc Bioinformatics 2016; 54: 1.30.31-31.30.33
  • 76 [Anonymous]. Online Mendelian Inheritance in Man, OMIM®. In: Baltimore, MD, USA: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University; 2018
  • 77 Sherry ST, Ward MH, Kholodov M. et al. dbSNP: the NCBI database of genetic variation. Nucleic Acids Res 2001; 29: 308-311
  • 78 [Anonymous]. NHLBI Exome Sequencing Project (ESP) Exome Variant Server. In; 2018
  • 79 Scott EM, Halees A, Itan Y. et al. Characterization of Greater Middle Eastern genetic variation for enhanced disease gene discovery. Nat Genet 2016; 48: 1071-1076
  • 80 Akbari MR, Fattahi Z, Beheshtian M et al. Iranome: A human genome variation database of eight major ethnic groups that live in Iran and neighboring countries in the Middle East. 67th Annual Meeting of The American Society of Human Genetics, 2017; 2017; Orlando, FL, USA
  • 81 Walters-Sen LC, Hashimoto S, Thrush DL. et al. Variability in pathogenicity prediction programs: impact on clinical diagnostics. Mol Genet Genomic Med 2015; 3: 99-110
  • 82 Schwarz JM, Cooper DN, Schuelke M. et al. MutationTaster2: Mutation prediction for the deep-sequencing age. Nat Methods 2014; 11: 361-362
  • 83 Adzhubei IA, Schmidt S, Peshkin L. et al. A method and server for predicting damaging missense mutations. Nat Methods 2010; 7: 248-249
  • 84 Kumar P, Henikoff S, Ng PC. Predicting the effects of coding non-synonymous variants on protein function using the SIFT algorithm. Nature Protocols 2009; 4: 1073-1082
  • 85 Vaser R, Adusumalli S, Leng SN. et al. SIFT missense predictions for genomes. Nat Protoc 2016; 11: 1-9
  • 86 Xiong HY, Alipanahi B, Lee LJ. et al. RNA splicing. The human splicing code reveals new insights into the genetic determinants of disease. Science 2015; 9: 1254806
  • 87 Majoros WH, Holt C, Campbell MS et al. Predicting Gene Structure Changes Resulting from Genetic Variants via Exon Definition Features. LID - 10.1093/bioinformatics/bty324 [doi]. Bioinformatics 2018 [Epub ahead of print]
  • 88 Desmet FO, Hamroun D, Lalande M. et al. Human Splicing Finder: an online bioinformatics tool to predict splicing signals. Nucleic Acids Res 2009; 37: e67
  • 89 Pertea M, Lin X, Salzberg SL. GeneSplicer: a new computational method for splice site prediction. Nucleic Acids Res 2001; 29: 1185-1190
  • 90 Yeo G, Burge CB. Maximum entropy modeling of short sequence motifs with applications to RNA splicing signals. J Comput Biol 2004; 11: 377-394
  • 91 Reese MG, Eeckman FH, Kulp D. et al. Improved splice site detection in Genie. J Comput Biol 1997; 4: 311-323
  • 92 Landrum MJ, Lee JM, Benson M. et al. ClinVar: public archive of interpretations of clinically relevant variants. Nucleic Acids Res 2016; 44: D862-D868
  • 93 Fokkema IF, Taschner PE, Schaafsma GC. et al. LOVD v.2.0: the next generation in gene variant databases. Hum Mutat 2011; 32: 557-563
  • 94 Akle S, Chun S, Jordan DM. et al. Mitigating false-positive associations in rare disease gene discovery. Hum Mutat 2015; 36: 998-1003
  • 95 Eisenberger T, Di Donato N, Baig SM. et al. Targeted and Genomewide NGS Data Disqualify Mutations in MYO1A, the “DFNA48 Gene”, as a Cause of Deafness. Hum Mutat 2014; 35: 565-570
  • 96 Hildebrand MS, DeLuca AP, Taylor KR. et al. A contemporary review of AudioGene audioprofiling: a machine-based candidate gene prediction tool for autosomal dominant nonsyndromic hearing loss. Laryngoscope 2009; 119: 2211-2215
  • 97 Taylor KR, Booth KT, Azaiez H. et al. Audioprofile Surfaces: The 21st Century Audiogram. Ann Otol Rhinol Laryngol 2016; 125: 361-368
  • 98 Taylor KR, Deluca AP, Shearer AE. et al. AudioGene: predicting hearing loss genotypes from phenotypes to guide genetic screening. Hum Mutat 2013; 34: 539-545
  • 99 Shen J, Scheffer DI, Kwan KY. et al. SHIELD: an integrative gene expression database for inner ear research. Database (Oxford) 2015; 2015: bav071
  • 100 Hertzano R, Orvis J. gEAR Portal. In; 2018
  • 101 Tandy-Connor S, Guiltinan J, Krempely K et al. False-positive results released by direct-to-consumer genetic tests highlight the importance of clinical confirmation testing for appropriate patient care. LID – 10.1038/gim.2018.38 [doi]. Genet Med 2018 [Epub ahead of print]
  • 102 Oza A, DiStefano M, Hemphill S. et al. Expert Specification of the ACMG/AMP Variant Interpretation Guidelines for Genetic Hearing Loss. bioRxiv 2018; DOI: 10.1101/313734 .
  • 103 Hu H, Huff CD, Moore B. et al. VAAST 2.0: Improved Variant Classification and Disease-Gene Identification Using a Conservation-Controlled Amino Acid Substitution Matrix. Genet Epidemiol 2013; 37: 622-634
  • 104 Pollard KS, Hubisz MJ, Rosenbloom KR. et al. Detection of nonneutral substitution rates on mammalian phylogenies. Genome Res 2010; 20: 110-121
  • 105 Grantham R. Amino acid difference formula to help explain protein evolution. Science 1974; 185: 862-864
  • 106 Tang H, Wyckoff GJ, Lu J. et al. A universal evolutionary index for amino acid changes. Mol Biol Evol 2004; 21: 1548-1556
  • 107 Van Laer L, Coucke P, Mueller RF. et al. A common founder for the 35delG GJB2 gene mutation in connexin 26 hearing impairment. J Med Genet 2001; 38: 515-518
  • 108 Ballana E, Ventayol M, Rabionet R et al. The Connexin-deafness Homepage. In. September 8, 2018 ed; 2018
  • 109 Kircher M, Witten DM, Jain P. et al. A general framework for estimating the relative pathogenicity of human genetic variants. Nat Genet 2014; 46: 310-315
  • 110 Scriver CR. After the genome – the phenome?. J Inherit Metab Dis 2004; 27: 305-317
  • 111 Oetting WS, Robinson PN, Greenblatt MS, Cotton RG et al. Getting ready for the Human Phenome Project: the 2012 forum of the Human Variome Project. DOI: 10.1002/humu.22293
  • 112 Deans AR, Lewis SE, Huala E. et al. Finding Our Way through Phenotypes. Plos Biol 2015; 13: e1002033
  • 113 Poldrack RA, Congdon E, Triplett W. et al. A phenome-wide examination of neural and cognitive function. Sci Data 2016; 3: 160110
  • 114 Köhler S, Vasilevsky NA-O, Engelstad M et al. The Human Phenotype Ontology in 2017. DOI: 10.1038/sdata.2016.110
  • 115 Vasilevsky NA, Foster ED, Engelstad ME. et al. Plain-language medical vocabulary for precision diagnosis. Nat Genet 2018; 50: 474-476
  • 116 Gall T, Valkanas E, Bello C. et al. Defining Disease, Diagnosis, and Translational Medicine within a Homeostatic Perturbation Paradigm: The National Institutes of Health Undiagnosed Diseases Program Experience. Front Med 2017; 4: 62
  • 117 Hartel BP, Lofgren M, Huygen PL. et al. combination of two truncating mutations in USH2A causes more severe and progressive hearing impairment in Usher syndrome type IIa. Hear Res 2016; 339: 60-68
  • 118 Morton CC. 2014 Presidential Address: The Time of Our Lives. Am J Hum Genet 2015; 96: 347-351