CellFree DNA Prenatal Screen

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General Information

Lab Name
CellFree DNA Prenatal Screen
Lab Code
PDNAS
Epic Ordering
Cell-Free DNA Prenatal Screen
Description

This screening test evaluates the copy number state for all 46 chromosomes, including common aneuploidies (trisomy 13, 18, 21, and sex chromosomes). Highly recommend individualized patient-provider discussion prior to ordering.

Ordering Requirements:

  • Singleton Pregnancies:
    • For orders submitted electronically via Epic, providers must complete the Clinical Order Questions in Epic or submit a completed UW Genetics Clinical Lab Request Form.
    • Submissions from outside (reference lab) clients must be accompanied by a completed UW Genetics Clinical Lab Request form.
  • Twin Pregnancies: For twin pregnancies, samples are sent out to Illumina. Refer to separate informational test guide #484, “Send Out Cell Free DNA Aneuploidy Screen.”
    • A completed UW-MT Genetics Clinical Lab Request Form is required for all orders.
    • Provider signature on the form is mandatory. Failure to provide a signed requisition form may result in testing delays or cancellations.
Forms & Requisitions

UW DLMP Genetics Clinical Lab Request Form

Synonyms
cell-free fetal DNA, cfDNA, Down syndrome, fetal chromosome aneuploidy screen, NIPS, NIPT, noninvasive prenatal screening, noninvasive prenatal testing, Placental DNA, Trisomy 13, Trisomy 18, Trisomy 21, Turner syndrome
Components

Interpretation

Method

Massively parallel sequencing of total cell-free DNA (cfDNA)

Reference Range
See individual components
Guidelines

Ordering & Collection

Specimen Type
Whole blood
Collection

Two 10 mL whole blood in Streck Cell-Free DNA BCT® tubes (mottled black and tan).

Gently mix blood by inverting tube 8-10 times.

Do not send samples via pneumatic tube system. Samples collected in Streck tubes must be walked to the laboratory.

Forms & Requisitions

UW DLMP Genetics Clinical Lab Request Form

Handling Instructions

Walk samples to the laboratory after collection. Do not transport via pneumatic tube system, as this may compromise the collection tube.

Quantity
requested: 20 mL whole blood
minimum: 7 mL whole blood

Processing

Processing

Note: For twin pregnancies, refer to informational test catalog “Send Out Cell Free DNA Aneuploidy Screen.” [484]

Store whole blood at room temperature. Do not Freeze. A completed Genetics Cell Free DNA Prenatal Screen request slip must accompany submissions.

SPS:

At the cfDNA Panel (PDNAP) prompt, enter PSFULL for "Full prenatal test with chromosomes 21, 18, 13 PLUS sex chromosome aneuploidies."

Enter PSAU for "Limited prenatal test for chromosomes 21, 18, 13 ONLY."

Stability: Ambient: 5 days

Transport Temperature

Performance

LIS Dept Code
Genetics (GEN)
Performing Location(s)
UW-MT Genetics

Attention: Genetics Lab
Clinical lab, Room NW220
University of Washington Medical Center
1959 NE Pacific Street
Seattle, WA 98195

Tel: 206-598–6429 M–F (7:30 AM–4:00 PM)
Fax: 206-598–0304
Lab email: genelab@uw.edu

Tel (EXOME only): 206-543-0459

Manager

Rebecca Gaulin, rgaulin@uw.edu

Genetic Counselors

Angela Jacobson, MS, LGC agibson@uw.edu
Sarah Paolucci, MA, MS, LGC, spaolucc@uw.edu
Jenna Huey, MS, LGC, jlhuey@uw.edu
Sandra Coe, MS,LGC, scoe20@uw.edu
Dru Leistritz, MS, LGC, dru2@uw.edu (EXOME testing only)

Variant Review Scientist

Ankita Jhuraney, PhD

Faculty

Colin C. Pritchard, MD, PhD
Brian H. Shirts, MD, PhD
Christina Lockwood, PhD, DABCC
Stephen Salipante, MD, PhD
Eric Konnick, MD, MS
Niklas Krumm, MD,PhD
Vera Paulson, MD, PhD
Jillian Buchan, PhD, FACMG

Frequency
Turnaround time 8-10 business days
Available STAT?
No

Billing & Coding

CPT codes
81420
Billing Comments

81420

LOINC
73967-2