FISH – 22q11 deletion or 22q13 deletion syndromes

Diagnostic Use

Fluorescence in situ hybridisation (FISH) using locus-specific probes are applied to identify and confirm a diagnosis of both 22q11 deletion and 22q13 deletion syndromes.
The test should be requested when the clinical diagnosis is firm, when urgency is required or for family follow-up studies of a known 22q11 (or 22q13) deletion. Otherwise, microarray testing is the preferred test in most cases, as it detects all currently known microdeletion syndromes in one assay. See microarray for further information

Department

Genetics - Cytogenetics

Delphic Registration Code

CTGN

Synonyms

22q11 microdeletion
DiGeorge Syndrome
VCFS

Turnaround Time

18 days

Test Code

5445

Specimen Type

• Whole Blood
• Amniotic Fluid
• Chorionic Villus (CVS)

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Acceptable

• RPMI (Tissue)

Preferred Sample Volume (ml)

3

Minimum Sample Volume (ml)

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Preferred Sample Volume (ml)

1

Minimum Sample Volume (ml)

0.5

Additional Specimen Information

Whole blood is required for genetic testing; please do not centrifuge blood tubes.
Rapid prenatal 22q FISH can be performed on uncultured cells. For this please send amniotic fluid (3ml minimum) or chorionic villus tissue (5mg minimum).
Do not refrigerate or freeze.

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Interpretation

Comment on report

Reference Intervals

Comment on report

Test Method

Metaphase FISH - fluorescently-labelled DNA probes specific to a gene or region of interest are applied and hybridised to standard cytogenetic preparations on glass slides. Probe signals are visualised on chromosomes 'in situ' by fluorescent microscopy to determine copy number and relative location of the region of interest.
Rapid interphase FISH - fluorescently-labelled DNA probes specific to a gene or region of interest are applied and hybridised to uncultured cells fixed to glass slides. Probe signals are visualised in nuclei only by fluorescent microscopy to determine copy number of the region of interest.

Depending on the application, FISH is performed using metaphase chromosomes (cultured cells only) or interphase nuclei (uncultured or cultured).

Non-Funded Test Cost

$565.53 (Exclusive of GST)

Urgent testing by arrangement. Urgent turnaround time 5 days.

Contact Information

Enquiry Form