Noonan Syndrome, Fetal Analysis

CPT 81442

Test Details

Turnaround Time

14 - 21 days (In some cases, additional time may be required for confirmatory or reflex tests. If culture is needed, an additional 14 - 21 days may be required. Additional culture fee may be applied.)

Use

This test is used for prenatal diagnosis for at-risk pregnancies or when abnormalities are seen on fetal ultrasound.

Special Instructions

Labcorp clients with 8-digit client account numbers should call 800-345-4363 and Labcorp Genetics & Women's Health clients with 6-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.

Test Includes

This test includes the following genes: BRAF, CBL, HRAS, KRAS, LZTR1, MAP2K1, MAP2K2, MRAS, NRAS, PPP1CB, PTPN11, RAF1, RASA2, RIT1, RRAS, SHOC2, SOS1, SOS2 and SPRED1.

This test includes the following genes: BRAF, CBL, HRAS, KRAS, LZTR1, MAP2K1, MAP2K2, MRAS, NRAS, PPP1CB, PTPN11, RAF1, RASA2, RIT1, RRAS, SHOC2, SOS1, SOS2 and SPRED.

This test includes the following genes: BRAF, CBL, HRAS, KRAS, LZTR1, MAP2K1, MAP2K2, MRAS, NRAS, PPP1CB, PTPN11, RAF1, RASA2, RIT1, RRAS, SHOC2, SOS1, SOS2 and SPRED1.

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 over 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.

Methodology

Noonan syndrome: Next Generation Sequencing to identify genetic variants, including small nucleotide variants (SNVs), insertions and deletions.

Maternal cell contamination analysis (MCC): Analysis of short tandem repeat markers by multiplex fluorescent polymerase chain reaction (PCR) and capillary electrophoresis.

Related Documents

References

Ali MM, Chasen ST, Norton ME. Testing for Noonan syndrome after increased nuchal translucency. Prenat Diagn. 2017 Aug;37(8):750-753.28569377
Stuurman KE, Joosten M, van der Burgt I, et al. Prenatal ultrasound findings of rasopathies in a cohort of 424 fetuses: update on genetic testing in the NGS era. J Med Genet. 2019 Oct;56(10):654-661.31040167

Specimen Requirements

Information on collection, storage, and volume

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: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 4 mL cord blood (If amniotic fluid or CVS are cultured at another facility, please maintain back-up cultures.)

Amniotic fluid: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 4 mL cord blood (If amniotic fluid or CVS are cultured at another facility, please maintain back-up cultures.)

Amniotic fluid: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 4 mL cord blood (If amniotic fluid or CVS are cultured at another facility, please maintain back-up cultures.)

Amniotic fluid: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 4 mL cord blood (If amniotic fluid or CVS are cultured at another facility, please maintain back-up cultures.)

Amniotic fluid: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 4 mL cord blood (If amniotic fluid or CVS are cultured at another facility, please maintain back-up cultures.)

Minimum Volume

Amniotic fluid: 20 mL; CVS: 20 mg; amniotic fluid and CVS culture: two confluent T-25 flasks or 3 mL cord blood

Container

Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask; cord blood: yellow-top (ACD-A) or lavender-top (EDTA) tubes

Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask; cord blood: yellow-top (ACD-A) or lavender-top (EDTA) tubes

Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask; cord blood: yellow-top (ACD-A) or lavender-top (EDTA) tubes

Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask; cord blood: yellow-top (ACD-A) or lavender-top (EDTA) tubes

Amniotic fluid or CVS: sterile plastic conical tube or T-25 flask; cord blood: yellow-top (ACD-A) or lavender-top (EDTA) tubes

Storage Instructions

Maintain specimen at room temperature. Do not freeze.

Causes for Rejection

Frozen or hemolyzed specimen; quantity not sufficient for analysis; improper container

Collection

Standard sterile techniques; transfer aseptically to sterile tubes. Amniotic fluid: Discard first 2 mL of fluid aspirated to avoid maternal cell contamination.