title: Initial clinical laboratory experience in noninvasive prenatal testing for fetal aneuploidy from maternal plasma DNA samples.
abstract: OBJECTIVE
  The aim of this study is to report the experience of noninvasive prenatal DNA testing using massively parallel sequencing in an accredited clinical laboratory.
  
  
  METHODS
  Laboratory information was examined for blood samples received for testing between February and November 2012 for chromosome 21 (Chr21), Chr18, and Chr13. Monosomy X (MX) testing was available from July 2012 for cystic hygroma indication. Outcomes were collected from providers on samples with positive results.
  
  
  RESULTS
  There were 5974 samples tested, and results were issued within an average of 5.1 business days. Aneuploidy was detected in 284 (4.8%) samples (155 Chr21, 66 Chr18, 19 Chr13, 40 MX, and four double aneuploidy). Follow-ups are available for 245/284 (86%), and 77/284 (27.1%) are confirmed, including one double-aneuploidy case concordant with cytogenetics from maternal malignancy. Fourteen (0.2%) discordant (putative false-positive) results (one Chr21, six Chr18, three Chr13, three MX, and one Chr21/13) have been identified. Five (0.08%) false-negative cases are reported (two trisomy 21, two trisomy 18, and one MX). In 170 (2.8%) cases, the result for a single chromosome was indefinite.
  
  
  CONCLUSIONS
  This report suggests that clinical testing of maternal cell-free DNA for fetal aneuploidy operates within performance parameters established in validation studies. Noninvasive prenatal testing is sensitive to biological contributions from placental and maternal sources.
authors.affiliation: Genetic Services, Verinata Health, Inc., Redwood City, CA, USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Futch
authors.forename: John
authors.initials: J
authors.lastname: Spinosa
authors.forename: Sucheta
authors.initials: S
authors.lastname: Bhatt
authors.forename: Eileen
authors.initials: E
authors.lastname: de Feo
authors.forename: Richard P
authors.initials: RP
authors.lastname: Rava
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Sehnert
mesh_terms: D000293:Adolescent; D000328:Adult; D000782:Aneuploidy; D004247:DNA / Q000097:blood* / Q000235:genetics*; D017598:Efficiency, Organizational; D005260:Female; D005333:Fetus / Q000378:metabolism; D005820:Genetic Testing / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D007755:Laboratories, Hospital / Q000458:organization & administration; D008875:Middle Aged; D009035:Mothers; D011247:Pregnancy / Q000097:blood; D011296:Prenatal Diagnosis / Q000379:methods* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D004247:DNA