title: [Analysis of copy number variations in 66 children with unexplained mental retardation/developmental delay using chromosomal microarrays].
abstract: OBJECTIVE
  To investigate clinically relevant copy number variations (CNV) in patients with unexplained mental retardation/developmental delay (MR/DD) through chromosomal microarray analysis (CMA).
  
  
  METHODS
  Sixty-six patients with unexplained MR/DD were analyzed with CMA. All identified CNVs were verified with database of genomic variations (DGV), DECIPHER, ISCA and the literature.
  
  
  RESULTS
  Nineteen clinically relevant CNVs were detected among the 16 individuals. The diagnostic yield for the MR/DD patients was 24.2%. The most common abnormality was Phelan-McDermid syndrome (3/16, 18.8%), which was followed by Prader-Willi syndrome/Angelman syndrome (2/16, 12.5%) and Wolf-Hirschhorn syndrome (2/16, 12.5%).
  
  
  CONCLUSIONS
  CNVs are one of the most common causes for unexplained MR/DD. CMA can improve the detection rate of CNVs and confer genetic testing with greater sensitivity in elucidating the diagnosis for unexplained MR/DD.
authors.affiliation: Department of Pediatric Endocrinology, Genetic and Metabolism, Shanghai Institute of Pediatric Research, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, P. R. China. qiuwenjuanxh@163.com.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Li
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Qiu
authors.forename: Jun
authors.initials: J
authors.lastname: Ye
authors.forename: Lianshu
authors.initials: L
authors.lastname: Han
authors.forename: Huiwen
authors.initials: H
authors.lastname: Zhang
authors.forename: Xuefan
authors.initials: X
authors.lastname: Gu
mesh_terms: D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D056915:DNA Copy Number Variations; D002658:Developmental Disabilities / Q000235:genetics*; D005260:Female; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000235:genetics*; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis