title: Rapid diagnosis of pseudomosaicism in a case of Level II mosaicism for trisomy 5 in a single colony from an in situ culture of amniocytes and a review of mosaic trisomy 5 at amniocentesis.
abstract: OBJECTIVE
  We present prenatal diagnosis of pseudomosaicism for trisomy 5 and a review of the literature of mosaic trisomy 5 at amniocentesis.
  
  
  METHODS
  A 39-year-old woman underwent amniocentesis at 17 weeks of gestation, which revealed a karyotype of 47,XY,+5[1]/46,XY[20]. The single colony with trisomy 5 had five metaphase cells, and all five cells had the karyotype of 47,XY,+5. Repeat amniocentesis performed at 20 weeks of gestation revealed a karyotype of 46,XY in 27/27 colonies. Simultaneously, interphase fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), and quantitative fluorescent polymerase chain reaction (QF-PCR) were performed on uncultured amniocytes. Interphase FISH revealed no trisomy 5 in 100 uncultured amniocytes. aCGH revealed no genomic imbalance. QF-PCR excluded uniparental disomy 5. A healthy 3662-g male baby was delivered with a normal karyotype in cord blood and 3.75% (3/80 cells) of trisomy 5 cells in uncultured urinary cells compared with 0.95% (1/105 cells) of trisomy 5 cells in normal control examined by FISH at 1.5 months of age. A review of seven cases with mosaic trisomy 5 at amniocentesis shows that 4/7 had clinically normal outcome, 3/7 had structural defects, mainly the heart, 6/6 had normal karyotype in blood, and 2/3 had mosaic trisomy 5 in the fetal tissues.
  
  
  CONCLUSIONS
  Prenatal diagnosis of mosaic trisomy 5 should alert the possibility of fetal structural abnormalities, especially the heart, and culture artifacts. We suggest that the application of molecular cytogenetic techniques such as aCGH, interphase FISH, and QF-PCR on uncultured amniocytes is useful in our understanding of the mosaic status at repeat amniocentesis.
authors: Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan; Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan; School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; Institute of Clinical and Community Health Nursing, National Yang-Ming University, Taipei, Taiwan; Department of Obstetrics and Gynecology, School of Medicine, National Yang-Ming University, Taipei, Taiwan. Electronic address: cpc_mmh@yahoo.com.
authors: Chih-Ping
authors: CP
authors: Chen
authors: Department of Obstetrics and Gynecology, Hsinchu MacKay Memorial Hospital, Hsinchu, Taiwan; Department of Molecular Cellular Biology, National Tsing Hua University, Hsinchu, Taiwan.
authors: Shing-Jyh
authors: SJ
authors: Chang
authors: Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.
authors: Schu-Rern
authors: SR
authors: Chern
authors: Gene Biodesign Co. Ltd, Taipei, Taiwan.
authors: Peih-Shan
authors: PS
authors: Wu
authors: Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan.
authors: Yen-Ni
authors: YN
authors: Chen
authors: Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan.
authors: Shin-Wen
authors: SW
authors: Chen
authors: Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan.
authors: Chien-Wen
authors: CW
authors: Yang
authors: Department of Obstetrics and Gynecology, MacKay Memorial Hospital, Taipei, Taiwan.
authors: Chen-Wen
authors: CW
authors: Pan
authors: Department of Medical Research, MacKay Memorial Hospital, Taipei, Taiwan; Department of Bioengineering, Tatung University, Taipei, Taiwan.
authors: Wayseen
authors: W
authors: Wang
mesh_terms: D000328:Adult; D000649:Amniocentesis / Q000379:methods*; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D055028:Comparative Genomic Hybridization / Q000379:methods; D020732:Cytogenetic Analysis / Q000379:methods; D005260:Female; D005312:Fetal Blood; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods; D007223:Infant; D059785:Karyotype; D007621:Karyotyping / Q000379:methods; D050498:Live Birth / Q000235:genetics; D008297:Male; D009030:Mosaicism / Q000196:embryology*; D011247:Pregnancy
keywords: amniocentesis; mosaic trisomy 5; prenatal diagnosis; pseudomosaicism; uncultured amniocytes