Fragile X Syndrome, Fetal Analysis
Also known as: Fragile X testing
Use
This test is used for prenatal diagnosis for pregnancies at risk for fragile X syndrome (FMR1).
Special Instructions
Labcorp clients with account numbers should contact a laboratory genetic coordinator before specimen collection. All fetal specimens, including cord blood, must be accompanied by a maternal blood, PurFlock buccal swab kit, or Oragene Dx 500 saliva kit for maternal cell contamination (MCC). A separate requisition is required for the maternal specimen.
Limitations
This test does not detect germline mosaicism, large chromosomal aberrations including rearrangements and gene fusions, interactions between variants, or repeat expansions. False positives or negatives may occur due to rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, somatic mosaicism, mislabeled samples, or erroneous family relationship representations. It has not been cleared or approved by the FDA, and variant classification may change as new information becomes available.
Methodology
PCR-based (PCR)
Biomarkers
LOINC Codes
- 21759-6
- 42784-9
- 31208-2
- 89993-0
- 42349-1
- 11951-1
- 21759-6
- 53039-4
- 8262-8
- 59266-7
- 55752-0
- 62385-0
- 8251-1
- 49549-9
- 75608-0
- 72486-4
- 51969-4
Result Turnaround Time
8-14 days
Related Documents
For more information, please review the documents below
Specimen
Other
Volume
20 mL
Minimum Volume
20 mL
Container
sterile plastic conical tube or T-25 flask
Collection Instructions
Amniotic fluid: Discard first 2 mL of fluid aspirated to avoid maternal cell contamination.
Storage Instructions
Maintain specimen at room temperature. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container