title: Performance of chromosomal microarray for patients with intellectual disabilities/developmental delay, autism, and multiple congenital anomalies in a Chinese cohort.
abstract: BACKGROUND
  Chromosomal microarray (CMA) is currently the first-tier genetic test for patients with idiopathic neuropsychiatric diseases in many countries. Its improved diagnostic yield over karyotyping and other molecular testing facilitates the identification of the underlying causes of neuropsychiatric diseases. In this study, we applied oligonucleotide array comparative genomic hybridization as the molecular genetic test in a Chinese cohort of children with DD/ID, autism or MCA.
  
  
  RESULTS
  CMA identified 7 clinically significant microduplications and 17 microdeletions in 19.0% (20/105) patients, with size of aberrant regions ranging from 11 kb to 10.7 Mb. Fourteen of the pathogenic copy number variant (CNV) detected corresponded to well known microdeletion or microduplication syndromes. Four overlapped with critical regions of recently identified genomic syndromes. We also identified a rare de novo 2.3 Mb deletion at 8p21.3-21.2 as a pathogenic submicroscopic CNV. We also identified two novel CNVs, one at Xq28 and the other at 12q21.31-q21.33, in two patients (1.9%) with unclear clinical significance. Overall, the detection rate of CMA is comparable to figures previously reported for accurately detect submicroscopic chromosomal imbalances and pathogenic CNVs except mosaicism, balanced translocation and inversion.
  
  
  CONCLUSIONS
  This study provided further evidence of an increased diagnostic yield of CMA and supported its use as a first line diagnostic tool for Chinese individuals with DD/ID, ASD, and MCA.
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China ; Prenatal genetic diagnosis laboratory, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
authors.forename: Wilson Wai Sing
authors.initials: WW
authors.lastname: Chong
authors.affiliation: Clinical Genetic Service, Department of Health, Hong Kong SAR, China.
authors.forename: Ivan Fai Man
authors.initials: IF
authors.lastname: Lo
authors.affiliation: Clinical Genetic Service, Department of Health, Hong Kong SAR, China.
authors.forename: Stephen Tak Sum
authors.initials: ST
authors.lastname: Lam
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China ; Prenatal genetic diagnosis laboratory, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
authors.forename: Chi Chiu
authors.initials: CC
authors.lastname: Wang
authors.affiliation: Clinical Genetic Service, Department of Health, Hong Kong SAR, China.
authors.forename: Ho Ming
authors.initials: HM
authors.lastname: Luk
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China ; Prenatal genetic diagnosis laboratory, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China.
authors.forename: Tak Yeung
authors.initials: TY
authors.lastname: Leung
authors.affiliation: Department of Obstetrics and Gynaecology, The Chinese University of Hong Kong, Hong Kong SAR, China ; Prenatal genetic diagnosis laboratory, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, Hong Kong SAR, China ; CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China ; Joint Centre with Utrecht University-Genetic Core, School of Biomedical Science, The Chinese University of Hong Kong, Hong Kong SAR, China.
authors.forename: Kwong Wai
authors.initials: KW
authors.lastname: Choy
keywords: Array CGH; Chromosomal microarray; Developmental delay; Intellectual disabilities; Multiple congenital anomalies