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.
Genetics - Cytogenetics
22q deletion FISH
Non-paediatric: 3-5 ml lithium heparin (green-top tube) peripheral blood, well-mixed
Paediatric or difficult bleed: 1ml lithium heparin (2 paediatric green-top tubes) peripheral blood, well-mixed
Clotted blood unacceptable
Ambient (8 - 24 degrees Celsius)
Do NOT centrifuge or freeze the sample
Comment within the report
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).
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.
Urgent turnaround time within 5 days