Fluorescence In Situ Hybridization (FISH)
FISH analysis with sequence-specific DNA probes. Assay performed by clinically certified cytogenetic technologists and reviewed by an ABMG-certified director, with results typically available in 10-15 days.
What it detects:
- Genomic sequence of interest
- Duplications or deletions >20Kb
- >2% mosaicism (for example: cultures where >2 of 100 cells are trisomy 12)
- Chromosomal location of genomic gains
- Chromosome fusions (breakaparts)
What it doesn’t detect:
- Changes in regions other than the probe-specific sequence
When to use:
- To confirm findings and refine breakpoints detected by g-banded karyotyping
- To confirm findings and localize genomic gains detected by aCGH analysis
- As a screen for microdeletions/duplications of known targets
- As a screen for aneuploidies other than X, 8, 12, and 17
