Test Details
Technology
Methodology
Cell-free DNA is isolated from the sample and analyzed using massively parallel sequencing technology.
Result Turnaround Time
3 - 5 days
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
For pregnancies at increased risk of fetal abnormalities, the MaterniT21 PLUS test delivers a comprehensive NIPT for the analysis of chromosomal regions including trisomies 21, 18 and 13, fetal sex, and an enhanced sequencing series that examines seven clinically relevant microdeletions and two additional chromosomal regions, trisomies 22 and 16.
Special Instructions
The following information must be provided with the test request form: patient's date of birth, gestational age, additional patient demographic information such as pregnancy type (singleton or multiple), donor egg status, and the clinical indications (including advanced maternal age, abnormal ultrasound, history suggestive of increased risk for aneuploidy, positive serum screen, or other indications).
Limitations
While the results of these tests are highly accurate, discordant results, including inaccurate fetal sex prediction, may occur due to placental, maternal or fetal mosaicism or neoplasm; vanishing twin; prior maternal organ transplant; or other causes. Cell-free DNA (cfDNA) testing does not replace the accuracy and precision of prenatal diagnosis with CVS or amniocentesis. A patient with a positive or high risk score test result should be referred for genetic counseling, and tests are not intended to identify pregnancies at risk for neural tube defects or ventral wall defects. cfDNA testing for whole chromosome abnormalities (including sex chromosomes) and for subchromosomal abnormalities could lead to the potential discovery of both fetal and maternal genomic abnormalities that could have minor or no clinical significance.
Evaluating the significance of a positive or non-reportable test result may involve both invasive prenatal testing and additional studies on the mother. Such investigations may lead to a diagnosis of maternal chromosomal or subchromosomal abnormalities, which on occasion may be associated with benign or malignant maternal neoplasms. cfDNA testing may not accurately identify fetal triploidy, balanced rearrangements or the precise locations of subchromosomal duplications or deletions; these may be detected by prenatal diagnosis with CVS or amniocentesis.
The ability to report results may be impacted by maternal body mass index (BMI), maternal weight, and/or maternal systemic lupus erythematosus (SLE). The results of this testing, including the benefits and limitations, should be discussed with a qualified health care provider. Pregnancy management decisions, including termination of the pregnancy, should not be based on the results of this test alone.
Specimen Requirements
Specimen
Whole blood
Volume
10 mL whole blood
Minimum Volume
8 mL whole blood
Container
Black-and-tan-top (Streck) tube (whole blood); Sequenom collection kits are available
Collection Instructions
Only the Sequenom collection kit can be used.
Storage Instructions
Room temperature; do not refrigerate or freeze. Keep out of direct sunlight. Samples must be shipped to Labcorp in a Sequenom collection kit.
Causes for Rejection
Gestational age less than nine weeks; expired or incorrect blood tubes (including non-glass tubes); quantity not sufficient for analysis; received more than seven days from collections; excessive hemolysis; frozen specimens
References
American College of Obstetricians and Gynecologists. Profile of Ob-Gyn Practice. ACOG Web site: http://www.acog.org/~/media/ Departments/Practice/ProfileofOb-gynPractice1991-2003.pdf? dmc=1&ts=20140216T0236326521. Accessed April 29, 2016.
Bianchi DW, et al. Genome-wide fetal aneuploidy detection by maternal plasma DNA sequencing. Obstet Gynecol. 2012 May;119(5):890-901. PubMed 22362253
Canick JA, et al. DNA sequencing of maternal plasma to identify Down syndrome and other trisomies in multiple gestations. Prenat Diagn. 2012 Aug;32(8):730-734. PubMed 22585317
Danielsson K. Trisomy 22 Types and the Link to Miscarriage. Very Well Family Web site: https://www.verywell.com/trisomy-22-and-miscarriage-2371299. Published April 2016. Accessed April 27, 2016. Updated October 30, 2018.
Disorders of Chromosome 16 Foundation. A Brief (and Basic) Overview of Chromosome 16 Disorders. Disorders of Chromosome 16 Foundation Web site: http://www.trisomy16.org/about/what_are_doc16.html. Published 2011. Accessed April 27, 2016.
Helgeson J, Wardrop J, Boomer T, et al. Clinical outcome of subchromosomal events detected by whole-genome noninvasive prenatal testing. Prenat Diagn. 2015 Oct;35(10):999-1004. PubMed 26088833
Mazloom AR, Dzakula Z, Oeth P, et al. Noninvasive prenatal detection of sex chromosomal aneuploidies by sequencing circulating cell-free DNA from maternal plasma. Prenat Diagn. 2013 Jun;33(6):591-597. PubMed 23592550
Norton ME, Brar H, Weiss J, et al. Non-invasive chromosomal evaluation (NICE) study: results of a multicenter, prospective, study for detection of fetal trisomy 21 and trisomy 18. Am J Obstet Gynecol. 2012 Aug;207(2):137.e1-e8. PubMed 22742782
Palomaki GE, Deciu C, Kloza EM, et al. DNA sequencing of maternal plasma reliably identifies trisomy 18 and trisomy 13, as well as Down syndrome: An international collaborative study. Genet Med. 2012 Mar;14(3):296-305. PubMed 22281937
Palomaki GE, Kloza EM, Lambert-Messerlian GM, et al. DNA sequencing of maternal plasma to detect Down syndrome: An international clinical validation study. Genet Med. 2011 Nov;13(11):913-920. PubMed 22005709
Pergament E, Cuckle H, Zimmermann B, et al. Single-nucleotide polymorphism-based noninvasive prenatal screening in a high-risk and low-risk cohort. Obstet Gynecol. 2014 Aug;124(2 Pt 1):210-218. PubMed 25004354
US National Library of Medicine. Angelman syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/angelman-syndrome#statistics. Published May 2015. Accessed April 27, 2016.
US National Library of Medicine. Cri-du-chat syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/cri-du-chat-syndrome#statistics. Published February 2014. Accessed April 27, 2016.
US National Library of Medicine. Down syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/down-syndrome# statistics. Published June 2012. Accessed April 27, 2016.
US National Library of Medicine. Jacobsen syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/jacobsen-syndrome#statistics. Published September 2015. Accessed April 27, 2016.
US National Library of Medicine. Klinefelter syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/klinefelter-syndrome#statistics. Published January 2013. Accessed April 27, 2016.
US National Library of Medicine. Prader-Willi syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/prader-willi-syndrome#statistics. Published June 2014. Accessed April 27, 2016.
US National Library of Medicine. Triple X syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/triple-x-syndrome#statistics. Published June 2014. Accessed April 27, 2016.
US National Library of Medicine. Trisomy 13. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/trisomy-13# statistics. Published November 2013. Accessed April 27, 2016.
US National Library of Medicine. Trisomy 18. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/trisomy-18# statistics. Published March 2012. Accessed April 27, 2016.
US National Library of Medicine. Turner syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/turner-syndrome#statistics. Published January 2012. Accessed April 27, 2016.
US National Library of Medicine. Wolf-Hirschhorn syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/wolf-hirschhorn-syndrome#statistics. Published April 2012. Accessed April 27, 2016.
US National Library of Medicine. 1p36 deletion syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/1p36-deletion-syndrome#statistics. Published January 2014. Accessed April 27, 2016.
US National Library of Medicine. 22q11.2 deletion syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/22q112-deletion-syndrome#statistics. Published July 2013. Accessed April 27, 2016.
US National Library of Medicine. 47,XYY syndrome. Genetics Home Reference: Your Guide to Understanding Genetic Conditions Web site: https://ghr.nlm.nih.gov/condition/47xyy-syndrome#statistics. Published January 2009. Accessed April 27, 2016.