Diagnostic value of exome and whole genome sequencing in craniosynostosis

J Med Genet. 2017 Apr;54(4):260-268. doi: 10.1136/jmedgenet-2016-104215. Epub 2016 Nov 24.

Abstract

Background: Craniosynostosis, the premature fusion of one or more cranial sutures, occurs in ∼1 in 2250 births, either in isolation or as part of a syndrome. Mutations in at least 57 genes have been associated with craniosynostosis, but only a minority of these are included in routine laboratory genetic testing.

Methods: We used exome or whole genome sequencing to seek a genetic cause in a cohort of 40 subjects with craniosynostosis, selected by clinical or molecular geneticists as being high-priority cases, and in whom prior clinically driven genetic testing had been negative.

Results: We identified likely associated mutations in 15 patients (37.5%), involving 14 different genes. All genes were mutated in single families, except for IL11RA (two families). We classified the other positive diagnoses as follows: commonly mutated craniosynostosis genes with atypical presentation (EFNB1, TWIST1); other core craniosynostosis genes (CDC45, MSX2, ZIC1); genes for which mutations are only rarely associated with craniosynostosis (FBN1, HUWE1, KRAS, STAT3); and known disease genes for which a causal relationship with craniosynostosis is currently unknown (AHDC1, NTRK2). In two further families, likely novel disease genes are currently undergoing functional validation. In 5 of the 15 positive cases, the (previously unanticipated) molecular diagnosis had immediate, actionable consequences for either genetic or medical management (mutations in EFNB1, FBN1, KRAS, NTRK2, STAT3).

Conclusions: This substantial genetic heterogeneity, and the multiple actionable mutations identified, emphasises the benefits of exome/whole genome sequencing to identify causal mutations in craniosynostosis cases for which routine clinical testing has yielded negative results.

Keywords: Actionable mutation; Craniosynostosis; Exome/whole genome sequencing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Craniosynostoses / diagnosis
  • Craniosynostoses / genetics*
  • Craniosynostoses / pathology
  • Exome / genetics
  • Genetic Testing
  • Genome, Human*
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Mutation
  • Neoplasm Proteins / genetics*
  • Predictive Value of Tests

Substances

  • Neoplasm Proteins