title: Prenatal microarray analysis as second-tier diagnostic test: single-center prospective study.
abstract: OBJECTIVE
  To evaluate the usefulness of chromosome microarrays as a second-tier test in prenatal genetic testing.
  
  
  METHODS
  We prospectively analyzed 75 high-risk pregnancies undergoing invasive prenatal genetic testing in which the karyotype either was normal or had findings other than a common non-mosaic autosomal aneuploidy.
  
  
  RESULTS
  Chromosomal microarray analysis (CMA) was performed successfully in all cases. Pathological copy-number variations (CNVs) explaining the phenotypes were found in 11 cases (14.7%). Four cases were detected with an unbalanced translocation. In three of these cases, subsequent genetic analysis demonstrated that a parent was an unknown carrier of a balanced translocation. Among the 67 cases with normal karyo-types, submicroscopic rearrangements with pathological significance were detected in five (7.5%) and CNVs of unclear significance were detected in one (1.5%). CMA was able to discriminate correctly between true mosaicism and confined or pseudomosaicism in all six mosaic cases.
  
  
  CONCLUSIONS
  CMA is a valuable second-tier test in high-risk pregnancies for which identification or further delineation of genetic aberrations is important. Its higher resolution results in a higher detection rate of aberrant cases, with a clear clinical benefit for estimation of risk of recurrence.
authors.affiliation: Department of Obstetrics and Gynecology, Medical University of Vienna, Vienna, Austria.
authors.forename: M
authors.initials: M
authors.lastname: Schmid
authors.forename: S
authors.initials: S
authors.lastname: Stary
authors.forename: S
authors.initials: S
authors.lastname: Springer
authors.forename: D
authors.initials: D
authors.lastname: Bettelheim
authors.forename: P
authors.initials: P
authors.lastname: Husslein
authors.forename: B
authors.initials: B
authors.lastname: Streubel
mesh_terms: D002869:Chromosome Aberrations; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D059785:Karyotype; D007621:Karyotyping / Q000379:methods; D046228:Microarray Analysis / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D011446:Prospective Studies