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Test Identifier Information

 
Registration CodeCTGN
Method

High density array comparative genomic hybridization (aCGH) detects copy number changes [sometimes called copy number variants (CNVs)] in patient DNA. The microarray can detect microduplications and microdeletions around 100 times smaller than seen by conventional G-band chromosome analysis (karyotype). The inclusion of single nucleotide polymorphism (SNP) probes in the microarray design enables the detection of large regions of homozygosity, which can be indicative of recessive disease or uniparental disomy. The microarray provides a genome-wide analysis of DNA copy number changes, with targeted probe coverage in disease-associated regions. For further technical details about the method and platform design see technical summary information.

Results are reported as: 

  1. No clinically relevant copy number change
  2. Copy number change of uncertain or unknown significance
  3. Clinically significant copy number change  
  4. Clinically significant homozygosity, indicative of UPD
Diagnostic Use / Indications

This parental follow up testing is performed as required to further characterise a variant identified in a young adult, child or pregnancy.

Cytogenetic microarray can be used to diagnose any human genetic disorder resulting from copy number change, when the corresponding region of interest is represented on the array.

 

External Price$659.35(Exclusive of GST)
  

Specimen Collection

 
Pre-Testing Requirements

 Please complete a patient consent form before requesting this test. 

Specimen Collection Protocols

 

  1. This test needs fresh, whole blood cells. The specimen must be well mixed.
  2. Do NOT centrifuge or freeze the blood tubes and keep at ambient temperature.
  3. Genomic DNA is extracted from the specimen prior to testing. This incurs an additional charge. Laboratories may submit DNA for testing, although it is not preferred. Please provide a minimum of 2 micrograms of DNA at 200 nanograms/microlitre.
Patient SpecimenBlood: 3-4mL EDTA + optional 1mL lithium heparin
Paediatric SpecimenNot applicable
Sample Delivery to LabSame day or overnight courier, ambient
  

CHLabs Laboratory

 
DepartmentHaematology - Cytogenetics
Contact Details Email Email
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Contact Phone Number03 364 1425
Test Availability9am-5pm Monday to Friday
Turnaround TimeFamily follow-up: 6 weeks
Interpretation

Multiple databases and current literature from NCBI are used to determine the clinical significance of the any copy number variants (CNV) identified by the cytogenetics microarray. Associations between the patient phenotype and the gene content/function of the affected region(s), or the known syndrome inferred, are also necessary to link pathogenicity.  

Limitations: Cytogenetic microarray will not detect balanced rearrangements, very small imbalances, low level mosaicism or regions of homozygosity <5Mb, and some  uniparental disomy. The screening resolution of this test is 50 kb in known clinically significant regions and 160kb elsewhere in the genome. Only imbalances of clinical significance, or unclear significance >200 kb, will be reported. Imbalances considered to be benign will not be reported.

Delphic Number Test Number8048

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