FISH, general region-specific

Diagnostic Use

FISH has many applications and is particularly useful for:

• Family follow-up testing of well-recognised microdeletion syndromes.
eg. 22q11 deletion (HIRA), Williams syndrome ELN), Prader Willi/Angelman syndrome (15q11-q13)
• Sex determination studies, eg. neonates with ambiguous genitalia, ?disorders of sexual development.
Probes routinely applied:- SRY (Yp) and X centromere. Other probes applied as required (Y centromere, Yq12, X/Ypter, X/Yqter, SHOX).
• Rapid testing of neonates for trisomy 21 (or other aneuploidy).
• Haematological studies for specific gene rearrangements.

Department

Genetics - Cytogenetics

Delphic Registration Code

CTGN

Synonyms

22q deletion FISH
Aneuploidy screen
SRY FISH

Turnaround Time

18 days

Test Code

5445

Specimen Type

• Whole Blood

Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Preferred Sample Volume (ml)

5

No of Samples Required

1

Paediatric Specimen Requirements

Tube/Container Type:

Preferred

• Lithium Heparin - Non-gel (Green Cap)

Preferred Sample Volume (ml)

1

Additional Specimen Information

Non-paediatric: 3-5 ml lithium heparin (green-top tube) peripheral blood, well-mixed.
Send without delay, ideally same day or by overnight courier
Paediatric or difficult bleed: 1ml lithium heparin (2 paediatric green-top tubes) peripheral blood, well-mixed

Clotted blood unacceptable

Aliquot Instructions

Sample Type

• Whole Blood

Transport to Lab

Ambient (8 - 24 degrees Celsius)

Additional Referral/Aliquot Information

Do NOT centrifuge or freeze the sample

Interpretation

Comment within the report

Test Method

Fluorescence in situ hybridization (FISH) is a targeted technique in which DNA probes, labelled with different coloured fluorescent tags, are applied to cells on a glass slide, in order to visualize one or more specific regions of the genome.

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

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Urgent turnaround time within 5 days

Uncertainty of Measurement - FISH analysis targets specific chromosomal regions.
The probes used in the test will only detect rearrangements of and enumerate the specific chromosome regions they encompass.
If required, please contact this laboratory for further information.

Contact Information

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