title: Experience using a rapid assay for aneuploidy and microdeletion/microduplication detection in over 2,900 prenatal specimens.
abstract: BACKGROUND
  While microarray testing can identify chromosomal abnormalities missed by karyotyping, its prenatal use is often avoided in low-risk pregnancies due to the possible identification of variants of uncertain significance (VOUS).
  
  
  METHODS
  We tested 2,970 prenatal samples of all referral indications using a rapid BACs-on-Beads-based assay with probes for sex chromosomes, common autosomal aneuploidies, and 20 microdeletion/microduplication syndromes, designed as an alternative to microarray in low-risk pregnancies and an alternative to rapid aneuploidy testing in pregnancies also undergoing microarray analysis.
  
  
  RESULTS
  Interpretable results were obtained in 2,940 cases (99.0%), with 89% receiving results in 1 day. Aneuploidies were detected in 7.3% and partial chromosome abnormalities in 0.45% (n = 13), including 5 referred for maternal age, abnormal maternal serum screen, or isolated ultrasound markers. The added detection above karyotype was 1 in 745 in lower-risk cases with normal ultrasounds or isolated ultrasound markers/increased nuchal measurements and 1 in 165 for fetuses with structural/growth abnormalities. Neither false negatives nor false positives were found within test limitations. Female polyploidy could not be detected, while polyploidies with Y chromosomes were suspected and confirmed through additional analysis.
  
  
  CONCLUSIONS
  When combined with karyotyping, this assay provides increased interrogation of specific chromosomal regions, while limiting VOUS identification.
authors.affiliation: Signature Genomic Laboratories, PerkinElmer, Inc., Spokane, Wash., USA.
authors.forename: Jill A
authors.initials: JA
authors.lastname: Rosenfeld
authors.forename: S Anne
authors.initials: SA
authors.lastname: Morton
authors.forename: Cathryn
authors.initials: C
authors.lastname: Hummel
authors.forename: Scott G
authors.initials: SG
authors.lastname: Sulpizio
authors.forename: Lisa D
authors.initials: LD
authors.lastname: McDaniel
authors.forename: Roger A
authors.initials: RA
authors.lastname: Schultz
authors.forename: Beth S
authors.initials: BS
authors.lastname: Torchia
authors.forename: J Britt
authors.initials: JB
authors.lastname: Ravnan
authors.forename: Jay W
authors.initials: JW
authors.lastname: Ellison
authors.forename: Allan J
authors.initials: AJ
authors.lastname: Fisher
mesh_terms: D000328:Adult; D000782:Aneuploidy; D058674:Chromosome Duplication; D020732:Cytogenetic Analysis; D005260:Female; D006801:Humans; D008297:Male; D025202:Molecular Diagnostic Techniques / Q000706:statistics & numerical data*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000706:statistics & numerical data*; D012189:Retrospective Studies