Use of Targeted Exome Sequencing for Molecular Diagnosis of Skeletal Disorders

PLoS One. 2015 Sep 18;10(9):e0138314. doi: 10.1371/journal.pone.0138314. eCollection 2015.

Abstract

Genetic disorders of the skeleton comprise a large group of more than 450 clinically distinct and genetically heterogeneous diseases associated with mutations in more than 300 genes. Achieving a definitive diagnosis is complicated due to the genetic heterogeneity of these disorders, their individual rarity and their diverse radiographic presentations. We used targeted exome sequencing and designed a 1.4 Mb panel for simultaneous testing of more than 4,800 exons in 309 genes involved in skeletal disorders. DNA from 69 individuals from 66 families with a known or suspected clinical diagnosis of a skeletal disorder was analyzed. Of 36 cases with a specific clinical hypothesis with a known genetic basis, mutations were identified for eight cases (22%). Of 20 cases with a suspected skeletal disorder but without a specific diagnosis, four causative mutations were identified. Also included were 11 cases with a specific skeletal disorder but for which there was at the time no known associated gene. For these cases, one mutation was identified in a known skeletal disease genes, and re-evaluation of the clinical phenotype in this case changed the diagnoses from osteodysplasia syndrome to Apert syndrome. These results suggest that the NGS panel provides a fast, accurate and cost-effective molecular diagnostic tool for identifying mutations in a highly genetically heterogeneous set of disorders such as genetic skeletal disorders. The data also stress the importance of a thorough clinical evaluation before DNA sequencing. The strategy should be applicable to other groups of disorders in which the molecular basis is largely known.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bone Diseases, Developmental / diagnosis
  • Bone Diseases, Developmental / genetics*
  • Cohort Studies
  • DNA Mutational Analysis / methods
  • Exome / genetics*
  • Genetic Diseases, Inborn / diagnosis
  • Genetic Diseases, Inborn / genetics
  • Genetic Predisposition to Disease
  • Genetic Testing / methods
  • Humans
  • Molecular Diagnostic Techniques / methods*
  • Polymorphism, Single Nucleotide
  • Sequence Analysis, DNA / methods*

Grants and funding

RP—Conselho Nacional de Desenvolvimento Científico e Tecnológico—564537/2010-1—http://www.cnpq.br/. RP—Fundação de Apoio à Pesquisa do Distrito Federal—19300 487/2011—http://www.fap.df.gov.br/. RP DLP—Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—http://www.capes.gov.br/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.