title: Prenatal detection of a de novo Yqh-acrocentric translocation.
abstract: OBJECTIVE
  To identify the extra chromosomal material on 46,XX,21p+ for prenatal diagnosis.
  
  
  METHODS
  Conventional cytogenetic studies using GTG (G bands by trypsin using Giemsa) and CBG (C bands by barium hydroxide using Giemsa) techniques were performed on chromosomes at metaphase obtained from cultured amniocytes and parental blood lymphocytes. Molecular cytogenetic techniques, QF-PCR (quantitative fluorescent polymerase chain reaction), FISH (fluorescent in-situ hybridization), and DA-DAPI (Distamycin A and 4,6-diamino-2-phenylindole) staining, were then used to clarify the extra material present on fetal chromosome 21 p.
  
  
  RESULTS
  The extra material on fetal chromosome 21 p has originated from Yqh, most likely at PAR2 (the secondary pseudoautosomal region). The karyotype should be 46,XX,der(21)t(Y;21)(q12;p13)de novo.ish der(21)t(Y;21)(q12;p13) (EST Cdy16c07+).
  
  
  CONCLUSIONS
  This case demonstrates the usefulness of molecular techniques in the investigation of rare chromosomal rearrangements.
authors.affiliation: Prenatal Diagnostic and Counselling Department, Tsan Yuk Hospital. Sai Ying Pun, Hong Kong SAR, China. ng_lucy59@hotmail.com
authors.forename: Lucy K L
authors.initials: LK
authors.lastname: Ng
authors.forename: Yvonne K
authors.initials: YK
authors.lastname: Kwok
authors.forename: Linda Y F
authors.initials: LY
authors.lastname: Tang
authors.forename: Paulina P Y
authors.initials: PP
authors.lastname: Ng
authors.forename: A
authors.initials: A
authors.lastname: Ghosh
authors.forename: Elizabeth T
authors.initials: ET
authors.lastname: Lau
authors.forename: Mary H Y
authors.initials: MH
authors.lastname: Tang
mesh_terms: D000328:Adult; D000653:Amniotic Fluid / Q000166:cytology; D002478:Cells, Cultured; D002871:Chromosome Banding; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D005260:Female; D005333:Fetus / Q000378:metabolism*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008677:Metaphase / Q000235:genetics; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014178:Translocation, Genetic / Q000235:genetics*