title: Microarray testing in clinical diagnosis: an analysis of 5,300 New Zealand patients.
abstract: BACKGROUND
  The use of Microarray (array CGH) analysis has become a widely accepted front-line test replacing G banded chromosome studies for patients with an unexplained phenotype. We detail our findings of over 5300 cases.
  
  
  RESULTS
  Of 5369 pre and postnatal samples, copy number variants (CNVs) were detected in 28.3 %, of which ~40 % were deletions and ~60 % were duplications. 96.8 % of cases with a CNV <5 Mb would not have been detected by G banding. At least 4.9 % were determined to meet the minimum criteria for a known syndrome. Chromosome 17 provided the greatest proportion of pathogenic CNVs with 65 % classified as (likely) pathogenic. X chromosome CNVs were the most commonly detected accounting for 4.2 % of cases, 0.7 % of these being classified as cryptic (likely) pathogenic CNVs.
  
  
  CONCLUSIONS
  Microarray analysis as a primary testing strategy has led to a significant increase in the detection of CNVs (~29 % overall), with ~9 % carrying pathogenic CNVs and one syndromic case identified per 20 referred patients. We suggest these frequencies are consistent with other heterogeneous studies. Conversely, (likely) pathogenic X chromosome CNVs appear to be greater compared with previous studies.
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Adrian
authors.initials: A
authors.lastname: Mc Cormack
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Karen
authors.initials: K
authors.lastname: Claxton
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Fern
authors.initials: F
authors.lastname: Ashton
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Philip
authors.initials: P
authors.lastname: Asquith
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Edward
authors.initials: E
authors.lastname: Atack
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mazzaschi
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand ; Present address: Pacific Edge Ltd, 87 St David St, North Dunedin, 9016 New Zealand.
authors.forename: Paula
authors.initials: P
authors.lastname: Moverley
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Rachel
authors.initials: R
authors.lastname: O'Connor
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Methat
authors.initials: M
authors.lastname: Qorri
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Karen
authors.initials: K
authors.lastname: Sheath
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Donald R
authors.initials: DR
authors.lastname: Love
authors.affiliation: Diagnostic Genetics, LabPLUS, Auckland City Hospital, PO Box 110031, Auckland, 1148 New Zealand.
authors.forename: Alice M
authors.initials: AM
authors.lastname: George