PLoS ONE (Jan 2015)

Use of Targeted Exome Sequencing for Molecular Diagnosis of Skeletal Disorders.

  • Daniel L Polla,
  • Maria T O Cardoso,
  • Mayara C B Silva,
  • Isabela C C Cardoso,
  • Cristina T N Medina,
  • Rosenelle Araujo,
  • Camila C Fernandes,
  • Alessandra M M Reis,
  • Rosangela V de Andrade,
  • Rinaldo W Pereira,
  • Robert Pogue

DOI
https://doi.org/10.1371/journal.pone.0138314
Journal volume & issue
Vol. 10, no. 9
p. e0138314

Abstract

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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.