title: Comparison of chromosome analysis and chromosomal microarray analysis: what is the value of chromosome analysis in today's genomic array era?
abstract: OBJECTIVE
  Chromosomal microarray analysis enables the detection of microdeletions/duplications and has become the standard in clinical diagnostic testing for individuals with congenital anomalies and developmental disabilities. In the era of genomic arrays, the value of traditional chromosome analysis needs to be reassessed.
  
  
  METHODS
  We studied 3,710 unrelated patients by chromosomal microarray analysis and chromosome analysis simultaneously and compared the results.
  
  
  RESULTS
  We found that chromosomal microarray analysis detected the chromosomal imbalances that were identified by chromosome analysis with the exception of six cases (0.16%) that had mosaic abnormalities. Of note, one case showed mosaicism for two abnormal cell lines, resulting in a balanced net effect and a normal chromosomal microarray analysis. Further structural abnormalities such as unbalanced translocations, rings, and complex rearrangements were subsequently clarified by chromosome analysis in 18% of the cases with abnormal chromosomal microarray analysis results. Apparently balanced rearrangements were detected by chromosome analysis in 30 cases (0.8%).
  
  
  CONCLUSIONS
  Our data demonstrate that although chromosomal microarray analysis should be the first-tier test for clinical diagnosis of chromosome abnormalities, chromosome analysis remains valuable in the detection of mosaicism and delineation of chromosomal structural rearrangements.
authors.affiliation: Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA. wbi@bcm.tmc.edu
authors.forename: Weimin
authors.initials: W
authors.lastname: Bi
authors.forename: Caroline
authors.initials: C
authors.lastname: Borgan
authors.forename: Amber N
authors.initials: AN
authors.lastname: Pursley
authors.forename: Patricia
authors.initials: P
authors.lastname: Hixson
authors.forename: Chad A
authors.initials: CA
authors.lastname: Shaw
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Bacino
authors.forename: Seema R
authors.initials: SR
authors.lastname: Lalani
authors.forename: Ankita
authors.initials: A
authors.lastname: Patel
authors.forename: Pawel
authors.initials: P
authors.lastname: Stankiewicz
authors.forename: James R
authors.initials: JR
authors.lastname: Lupski
authors.forename: Arthur L
authors.initials: AL
authors.lastname: Beaudet
authors.forename: Sau Wai
authors.initials: SW
authors.lastname: Cheung
mesh_terms: D002869:Chromosome Aberrations; D002871:Chromosome Banding; D020732:Cytogenetic Analysis / Q000379:methods; D056915:DNA Copy Number Variations; D023281:Genomics / Q000379:methods; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D009030:Mosaicism; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D014178:Translocation, Genetic