title: Validation of a semiconductor next-generation sequencing-based protocol for preimplantation genetic diagnosis of reciprocal translocations.
abstract: OBJECTIVE
  We aim to validate a semiconductor next-generation sequencing (NGS)-based method to detect unbalanced chromosome translocation in preimplantation embryos.
  
  
  METHODS
  The study consisted of a blinded retrospective evaluation with NGS of 145 whole-genome amplification products obtained from biopsy of cleavage-stage embryos or blastocysts, derived from 33 couples carrying different balanced translocations. Consistency of NGS-based copy number assignments was evaluated and compared with the results obtained by array-comparative genomic hybridization.
  
  
  RESULTS
  Reliably identified with the NGS-based protocol were 162 segmental imbalances derived from 33 different chromosomal translocations, with the smallest detectable chromosomal segment being 5 Mb in size. Of the 145 embryos analysed, 20 (13.8%) were balanced, 43 (29.6%) were unbalanced, 53 (36.5%) were unbalanced and aneuploid, and 29 (20%) were balanced but aneuploid. NGS sensitivity for unbalanced/aneuploid chromosomal call (consistency of chromosome copy number assignment) was 99.75% (402/403), with a specificity of 100% (3077/3077). NGS specificity and sensitivity for unbalanced/aneuploid embryo call were 100%.
  
  
  CONCLUSIONS
  Next-generation sequencing can detect chromosome imbalances in embryos with the added benefit of simultaneous comprehensive aneuploidy screening. Given the high level of consistency with array-comparative genomic hybridization, NGS has been demonstrated to be a robust high-throughput technique ready for clinical application in preimplantation genetic diagnosis for chromosomal translocations, with potential advantages of automation, increased throughput and reduced cost.
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Bono
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Biricik
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Spizzichino
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Nuccitelli
authors.affiliation: Centre for Reproductive Medicine, European Hospital, Rome, Italy.
authors.forename: M G
authors.initials: MG
authors.lastname: Minasi
authors.affiliation: Centre for Reproductive Medicine, European Hospital, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Greco
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Spinella
authors.affiliation: GENOMA, Molecular Genetics Laboratory, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Fiorentino
mesh_terms: D005260:Female; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D008297:Male; D019836:Preimplantation Diagnosis / Q000379:methods*; D014178:Translocation, Genetic