title: Mosaic trisomy 15 at amniocentesis: Prenatal diagnosis, molecular genetic analysis and literature review.
abstract: OBJECTIVE
  To present prenatal diagnosis of mosaic trisomy 15 at amniocentesis.
  
  
  METHODS
  A 37-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Cytogenetic analysis of cultured amniocytes revealed a karyotype of 47,XY,+15[2]/46,XY[17]. She was referred for repeated amniocentesis at 19 weeks of gestation. Array comparative genomic hybridization (aCGH), interphase fluorescence in situ hybridization (FISH) and quantitative fluorescent polymerase chain reaction assays on uncultured amniocytes, conventional cytogenetic analysis and aCGH on cultured amniocytes, and FISH on uncultured urinary cells after birth were applied. Cordocentesis revealed a karyotype of 46,XY.
  
  
  RESULTS
  At repeated amniocentesis, cultured amniocytes revealed a karyotypes of 46,XY [22 colonies], FISH on uncultured amniocytes revealed 21.2% (22/104 cells) mosaicism for trisomy 15, aCGH on uncultured amniocytes revealed a genomic gain (log2 ratio = 0.3) in chromosome 15, quantitative fluorescent polymerase chain reaction on uncultured amniocytes excluded uniparental disomy 15 (UPD 15), and aCGH on culture amniocytes revealed no genomic imbalance in chromosome 15. A healthy 3700 g male baby was delivered at 38 weeks of gestation with no phenotypic abnormalities at age 6 months. FISH on uncultured urinary cells at birth and at age 6 months revealed mosaic trisomy 15 levels of 20% (13/65 cells) and 12.2% (6/49 cells), respectively.
  
  
  CONCLUSIONS
  Prenatal diagnosis of mosaic trisomy 15 at amniocentesis should alert doctors about the occurrence of UPD 15 and a clinically significant phenotype. The present case provides evidence for cytogenetic discrepancy between uncultured and cultured amniocytes in mosaic trisomy 15 at amniocentesis. It is possible that the abnormal cell lines of amniocytes with trisomy 15 disappear after long-term cell culture.
authors.affiliation: 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.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chen
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Schu-Rern
authors.initials: SR
authors.lastname: Chern
authors.affiliation: Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Yen-Ni
authors.initials: YN
authors.lastname: Chen
authors.affiliation: Gene Biodesign Co. Ltd., Taipei, Taiwan.
authors.forename: Peih-Shan
authors.initials: PS
authors.lastname: Wu
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Chien-Wen
authors.initials: CW
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
authors.forename: Li-Feng
authors.initials: LF
authors.lastname: Chen
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital, Taipei, Taiwan; Department of Bioengineering, Tatung University, Taipei, Taiwan.
authors.forename: Wayseen
authors.initials: W
authors.lastname: Wang
mesh_terms: D000328:Adult; D000649:Amniocentesis / Q000379:methods*; D002884:Chromosomes, Human, Pair 15; D020732:Cytogenetic Analysis / Q000379:methods*; D005260:Female; D047109:Fetal Development / Q000502:physiology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007231:Infant, Newborn; D007621:Karyotyping / Q000379:methods; D008297:Male; D008423:Maternal Age; D009030:Mosaicism; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis / Q000379:methods; D012016:Reference Values; D018570:Risk Assessment; D014314:Trisomy / Q000175:diagnosis*; D024182:Uniparental Disomy / Q000175:diagnosis*
keywords: amniocentesis; mosaic trisomy 15; mosaicism; trisomy 15