Array CGH

The array CGH analysis compares a patient’s entire genome with that of many other persons who do not exhibit any clinical signs with regard to the loss and gain of genetic material.

Identical quantities of DNA from the test person and reference DNA are marked with various fluorescent dyes and subsequently cohybridised on the array. The microarray itself is a collection of immobilised genomic DNA fragments (so-called oligonucleoids) arrayed on a glass slide. A genomic loss or gain in the patient’s sample compared to the reference DNA results in a shift of the hybridisation ratio causing the fluorescent dye to change colour which is detected by a laser scanner. Subsequently, the data are extracted and evaluated using special software.

 

Indication

The array CGH analysis is a high-resolution diagnostic test method that is indicated for patients with the following criteria:

  • developmental delays / mental retardation
  • dysmorphic features
  • congenital malformations (e.g. heart defect, renal deformity)
  • deformities and dysfunctions of the brain
  • prenatal and postnatal growth delay
  • specific growth abnormalities (e.g. microcephaly)
  • autistic features
  • combined occurrence of the above mentioned features

Moreover, array CGH analysis is suitable for the following questions:

  • detailed definition of the chromosome analysis: exact determination of the breakage point, exact characterisation of cytogenetic gains and losses
  •  clarifying structural chromosome changes that appear balanced in patients with unspecific dysmorphic features
  •  clarifying genomic rearrangements (e.g. marker chromosomes)

close

Sampling / shipping

Postnatal:

  • EDTA blood
    Infants and toddlers: 1 – 2 ml
    Children and adults: 3 – 5 ml
    Duration*: 4 weeks request form: Array CGH

Prenatal (no standard benefit at present):

  • Overall approx. 20 ml amniotic fluid / 30 mg chorionic villi for chromosome and array CGH analysis
    Important: EDTA / heparin blood* of the mother or the parents to exclude maternal contamination or for prompt further examination if the copy number variations are unclear.
    Duration**: 10 days request form: Prenatal diagnostics

* = Processing time after arrival of the sample in the laboratory
** = Processing time after cell culture

close

a member of SONIC HEALTHCARE