Chromosome Analysis, Amniotic Fluid, with Reflex to Genomic Microarray
Also known as: AF REFLEX
Use
This test is used to evaluate amniotic fluid for chromosomal abnormalities. It is particularly indicated when abnormal ultrasound findings, abnormal prenatal screening, or fetal demise suggest the need for testing. Chromosome analysis identifies visible numerical abnormalities, chromosomal rearrangements, and large deletions or duplications. In cases where the initial chromosome analysis shows normal results, no growth, or a rearrangement requiring further genomic characterization, the test reflexes to genomic microarray analysis.
Special Instructions
Counseling and informed consent are recommended for genetic testing, especially for New York clients where informed consent is required upon submission. Specimen preparation requires maintaining amniotic fluid at room temperature and not exposing it to extreme temperatures. Submission of a Prenatal Cytogenetics Patient History Form and informed consent forms accompanies the order, particularly for NY patients.
Limitations
The chromosome analysis process involves culturing living cells, which can introduce variability in the turnaround time. The standard methodology may not detect small rearrangements, low-level mosaicism, or submicroscopic deletions/duplications, which are detectable by genomic microarray analysis. Additionally, maternal cell contamination studies are recommended if testing reflexes to microarray.
New York Approved
Methodology
Chromosomal / Cytogenetics (G-Banding)
Biomarkers
LOINC Codes
- 33773-3
- 11502-2
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Amniotic Fluid
Volume
Not provided
Minimum Volume
Not provided
Container
sterile container
Storage Instructions
Transport 15-30 mL amniotic fluid at room temperature.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 48 hours |
| Frozen | Unacceptable |