Chromosome disorders due to non-disjunction of chromosomes 13, 18, 21, X, and Y together comprise the majority of the microscopically detectable chromosome disorders.
Analysis by Fluorescence In Situ Hybridization (FISH) allows for the most rapid detection of the most common chromosome disorders. Results can typically be reported in 24-48 hours from the time of receipt.
Concurrent G-banded chromosome analysis with or without chromosomal microarray is recommended.
FISH for aneuploidy is appropriate for the following indications:
- Multiple congenital anomalies
- Dysmorphic features
- Developmental delay
- Advanced maternal age (AMA)
- Abnormal ultrasound
- Abnormal serum screen
- Parental concern
- Increased nuchal translucency or nuchal fold
- Family history
Interphase FISH is performed on uncultured peripheral blood samples using commercially available probes.
FISH is very sensitive in the detection of aneuploidy. This probe set is specific to chromosomes 13, 18, 21, X, and Y. Only numerical abnormalities of these chromosomes will be detected. Validation for specificity and sensitivity are performed on each probe. Control probes are present in all probe sets.
Preferred specimen type: Whole Blood
Type: Whole Blood
In sodium heparin (green top) tube:
Infants (<2 years): 2-3 ml.
Children (>2 years): 3-5 ml.
Older Children & Adults: 5-10 ml.
Specimen Collection and Shipping: Ship sample at room temperature for receipt at EGL within 24 hours of collection. Do not refrigerate or freeze.
- Chromosomal Microarray, EmArray Cyto (test code VA)
- Chromosomal SNP array (test code CMSNP)
- Chromosome Analysis (test codes CA, CB, MM)