Determination of sensitivity and specificity of a novel gene dosage assay for prenatal screening of trisomy 21 syndrome

Clin Biochem. 2012 Feb;45(3):267-71. doi: 10.1016/j.clinbiochem.2011.11.013. Epub 2011 Dec 8.

Abstract

Objective: To compare the gene dosage results achieved by a novel multiplex quantitative assay with cytogenetic and quantitative fluorescent polymerase chain reaction (QF-PCR) analysis for prenatal screening of trisomy 21 syndrome on corresponding fetal samples.

Design and methods: Fetal samples (n=134) were collected from pregnant women considered high risk for having trisomy 21 affected fetus. Cytogenetic analysis and QF-PCR were performed. Then, the relative gene dosage of DSCAM and DYRK1A2 genes was determined on corresponding samples using comparative delta cycle of threshold (ΔC(T)) method.

Results: The mean gene dosage ratio was 1.55 ± 0.11 (95% CI:1.51-1.58) in trisomy 21 cases and 1.01 ± 0.12 (95% CI:0.98-1.03) in normal samples (p value<0.001). The results were in agreement to the results of cytogenetic and QF-PCR analysis with the overall specificity of 0.96 (95% CI:0.91-0.98) and the sensitivity of 0.80 (95% CI:0.49-0.94).

Conclusions: This gene dosage assay is appropriate for the screening of high risk pregnant women and is readily amenable to automation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosomes, Human, Pair 21 / genetics
  • Down Syndrome / diagnosis*
  • Down Syndrome / genetics*
  • Female
  • Fluorescence
  • Gene Dosage / genetics*
  • Humans
  • Linear Models
  • Pregnancy
  • Prenatal Diagnosis / methods*
  • Real-Time Polymerase Chain Reaction / methods*
  • Reproducibility of Results
  • Sensitivity and Specificity