title: aCGH on chorionic villi mirrors the complexity of fetoplacental mosaicism in prenatal diagnosis.
abstract: OBJECTIVE
  To describe the diagnostic performance of array comparative genomic hybridization (aCGH) in the presence of mosaicism in the fetoplacental unit using direct chorionic villi.
  
  
  METHODS
  In an ongoing study on the diagnostic performance of aCGH in 80 high-risk pregnancies, we studied three cases of placental mosaicism by carrying out aCGH on DNA of direct chorionic villi and chorionic villi cultures.
  
  
  RESULTS
  Case 1: A three- to fourfold dosage gain of the region 18p in aCGH on direct villi was due to two additional isochromosomes 18p confined to the cytotrophoblast. Case 2: aCGH on direct villi revealed a normal result, whereas trisomy 18 mosaicism was present in cultured cells. Case 3: aCGH identifies monosomy X and mosaic disomy of the region Xp11.21-Xq12, whereas this mosaic cell line is not present in the conventional chromosome preparation on the cytotrophoblast.
  
  
  CONCLUSIONS
  Although interpretation of aCGH results may be straightforward in the majority of cases, placental mosaicism may cause misinterpretations of rapid aCGH results on direct chorionic villi due to discrepant chromosomal constitutions of cytotrophoblast and mesenchymal villus core. Further investigations including cultures, fluorescence in situ hybridization and possible amniocentesis will still be required for interpretation of results.
authors.affiliation: Division of Medical Genetics, University Children's Hospital and Department of Biomedicine, Basel, Switzerland. Isabel.Filges@unibas.ch
authors.forename: Isabel
authors.initials: I
authors.lastname: Filges
authors.forename: Anjeung
authors.initials: A
authors.lastname: Kang
authors.forename: Vanessa
authors.initials: V
authors.lastname: Klug
authors.forename: Friedel
authors.initials: F
authors.lastname: Wenzel
authors.forename: Karl
authors.initials: K
authors.lastname: Heinimann
authors.forename: Sevgi
authors.initials: S
authors.lastname: Tercanli
authors.forename: Peter
authors.initials: P
authors.lastname: Miny
mesh_terms: D000328:Adult; D002824:Chorionic Villi / Q000737:chemistry*; D015193:Chorionic Villi Sampling / Q000379:methods; D002887:Chromosomes, Human, Pair 18; D055028:Comparative Genomic Hybridization / Q000379:methods*; D004247:DNA / Q000032:analysis*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009030:Mosaicism / Q000196:embryology*; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D014314:Trisomy / Q000175:diagnosis* / Q000235:genetics; D014327:Trophoblasts / Q000737:chemistry / Q000473:pathology
chemical_list: D004247:DNA