title: [Detection of mosaic trisomy 9 missed by conventional cytogenetics using SNP-array and fluorescence in situ hybridization].
abstract: OBJECTIVE
  To detect mosaic trisomy 9 missed by conventional cytogenetics.
  
  
  METHODS
  Peripheral blood genomic DNA from a girl with mental retardation was analyzed using Affymetrix CytoScan (TM) HD array. Fluorescence in situ hybridization (FISH) was also performed on samples from two patients.
  
  
  RESULTS
  The SNP-array analysis has revealed multiple duplications along chromosome 9. FISH analysis showed that, for the peripheral blood sample from one patient, 40 of 100 interphase cells and 15 of 100 metaphase cells carried trisomy 9. For the cord blood sample from another patient, 35 of 100 interphase cells and 10 of 100 cultured cells carried trisomy 9.
  
  
  CONCLUSIONS
  SNP-array is useful for detecting low-level mosaicism which may be missed by conventional cytogenetics. Combined with karyotype and microarray analyses, FISH is a focused and targeted approach for diagnosing mosaic trisomy. They may provide a useful tool for differentiating pseudomosaicisms from true mosaicisms.
authors.affiliation: Department of Reproductive Genetics, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China. xuchenming@zju.edu.cn.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Luo
authors.forename: Songzhang
authors.initials: S
authors.lastname: Chen
authors.forename: Hongge
authors.initials: H
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Pan
authors.forename: Min
authors.initials: M
authors.lastname: Shen
authors.forename: Fan
authors.initials: F
authors.lastname: Jin
authors.forename: Chenming
authors.initials: C
authors.lastname: Xu
mesh_terms: D000328:Adult; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007223:Infant; D008297:Male; D009030:Mosaicism / Q000196:embryology; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods*; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014314:Trisomy / Q000175:diagnosis* / Q000235:genetics*; D024182:Uniparental Disomy / Q000166:cytology / Q000175:diagnosis* / Q000235:genetics*