Multiplex targeted high-throughput sequencing in a series of 352 patients with congenital limb malformations

Hum Mutat. 2020 Jan;41(1):222-239. doi: 10.1002/humu.23912. Epub 2019 Sep 23.

Abstract

Congenital limb malformations (CLM) comprise many conditions affecting limbs and more than 150 associated genes have been reported. Due to this large heterogeneity, a high proportion of patients remains without a molecular diagnosis. In the last two decades, advances in high throughput sequencing have allowed new methodological strategies in clinical practice. Herein, we report the screening of 52 genes/regulatory sequences by multiplex high-throughput targeted sequencing, in a series of 352 patients affected with various CLM, over a 3-year period of time. Patients underwent a clinical triage by expert geneticists in CLM. A definitive diagnosis was achieved in 35.2% of patients, the yield varying considerably, depending on the phenotype. We identified 112 single nucleotide variants and 26 copy-number variations, of which 52 are novel pathogenic or likely pathogenic variants. In 6% of patients, variants of uncertain significance have been found in good candidate genes. We showed that multiplex targeted high-throughput sequencing works as an efficient and cost-effective tool in clinical practice for molecular diagnosis of congenital limb malformations. Careful clinical evaluation of patients may maximize the yield of CLM panel testing.

Keywords: genetics; limb malformation; molecular diagnosis; targeted high-throughput sequencing.

MeSH terms

  • Alleles
  • DNA Copy Number Variations
  • DNA Mutational Analysis
  • Female
  • Genetic Association Studies* / methods
  • Genetic Predisposition to Disease*
  • Genetic Testing*
  • High-Throughput Nucleotide Sequencing*
  • Humans
  • Limb Deformities, Congenital / diagnosis*
  • Limb Deformities, Congenital / genetics*
  • Male
  • Mutation
  • Phenotype
  • Radiography
  • Real-Time Polymerase Chain Reaction