Test Details
Methodology
Cystic fibrosis: Next-generation sequencing to identify 97 variants in the CFTR gene.
Maternal cell contamination analysis (MCC): Analysis of short tandem repeat markers by multiplex fluorescent polymerase chain reaction (PCR) and capillary electrophoresis.
Result Turnaround Time
8 - 14 days. If culture is needed, an additional 14 - 21 days may be required. Additional culture fee may be applied.
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
This test is used for prenatal diagnosis for pregnancies at risk for cystic fibrosis. Ninety-seven CFTR variants are included in this analysis.
Special Instructions
Labcorp clients with eight-digit client account numbers should call 800-345-4363, and Labcorp Genetics & Women's Health clients with six-digit client/subclient account numbers should call 800-255-7357 to speak with a laboratory genetic coordinator before collecting specimens. In some circumstances, specimens from both parents and other family members may be required. 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 should be submitted with the maternal specimen.
Limitations
Technologies used do not detect germline mosaicism and do not rule out the presence of large chromosomal aberrations including rearrangements and gene fusions, or variants in regions or genes not included in this test, or possible inter/intragenic interactions between variants, or repeat expansions. Variant classification and/or interpretation may change with time if more information becomes available. False positive or false negative results may occur for reasons that include: rare genetic variants, sex chromosome abnormalities, pseudogene interference, blood transfusions, bone marrow transplantation, somatic or tissue-specific mosaicism, mislabeled samples or erroneous representation of family relationships. This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Specimen Requirements
Specimen
Amniotic fluid or chorionic villus sample (CVS) or cultured cells or cord blood. Direct amniotic fluid or CVS specimen may be submitted; additional culture fee may be applied.
Volume
Amniotic fluid: 10 mL; or CVS: 10 mg; or amniotic fluid and CVS culture: one confluent T-25 flask; or 4 mL cord blood. If amniotic fluid or CVS are cultured at another facility, please maintain backup cultures.
Minimum Volume
Amniotic fluid: 10 mL; or CVS: 10 mg; or amniotic fluid and CVS culture: one confluent T-25 flask; or 3 mL cord blood
Container
Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask
Collection Instructions
Standard sterile techniques; transfer aseptically to sterile tubes.
Amniotic fluid: Discard first 2 mL of fluid aspirated to avoid maternal cell contamination.
Stability Requirements
Please ship expedited at room temperature.
Storage Instructions
Maintain specimen at room temperature. Do not freeze.
Causes for Rejection
Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container