Genome-wide cfDNA screening: clinical laboratory experience with the first 10,000 cases

Genet Med. 2017 Dec;19(12):1332-1337. doi: 10.1038/gim.2017.56. Epub 2017 Jun 15.

Abstract

PurposeInvasive diagnostic prenatal testing can provide the most comprehensive information about the genetic status of a fetus. Noninvasive prenatal screening methods, especially when using cell-free DNA (cfDNA), are often limited to reporting only on trisomies 21, 18, and 13 and sex chromosome aneuploidies. This can leave a significant number of chromosomal and subchromosomal copy-number variations undetected. In 2015, we launched a new genome-wide cfDNA screening test that has the potential to narrow this detection gap.MethodsHere, we review the results from the first 10,000 cases submitted to the Sequenom clinical laboratory for genome-wide cfDNA screening.ResultsThe high-risk indication for this cohort differed compared with standard cfDNA screening. More samples were submitted with ultrasound indications (25% compared with 13% for standard cfDNA screening) and fewer for advanced maternal age (51% for genome-wide screening versus 68% for standard cfDNA screening). A total of 554 positive calls were made, of which 164 were detectable only via genome-wide analysis.ConclusionThis reports indicates a difference in utilization compared with standard cfDNA screening, where positivity rates are higher and a large subset of positive calls could not have been made using standard cfDNA screening.

MeSH terms

  • Cell-Free Nucleic Acids*
  • Chromosome Aberrations
  • Clinical Laboratory Services / standards
  • Female
  • Genetic Diseases, Inborn / diagnosis*
  • Genetic Diseases, Inborn / genetics*
  • Genome-Wide Association Study*
  • Humans
  • Pregnancy
  • Prenatal Diagnosis / methods*
  • Prenatal Diagnosis / standards
  • Risk Factors
  • Sensitivity and Specificity

Substances

  • Cell-Free Nucleic Acids