-- SNP-based NIPT method reduces false positives and fetal sex errors --
Nov. 13, 2014 /PRNewswire/ — Natera, Inc., a leader in non-invasive genetic testing, today announced its study showing that the Panorama™ NIPT successfully identifies vanished twin, previously unrecognized twin, and triploid pregnancies. This study is available online and will be published in the January 2015 issue of American Journal of Obstetrics and Gynecology. This is the first peer-reviewed publication detailing the clinical identification of vanishing twin and triploid cases by NIPT.
In multiple gestation pregnancies, whether natural or through assisted reproduction, loss of one or more fetuses occurs in around 30% of cases. The lost co-twin is referred to as a vanished twin and it can leave residual DNA in the mother's system that can affect interpretation of the genetic state of the ongoing fetus. In the majority of cases, the fetal loss is due to a chromosomal abnormality.
"Identifying vanishing twin and triploid pregnancies with NIPT is clinically important," said Susan Gross, MD, chief medical officer for Natera and senior author on the paper. "Previous publications demonstrated a clear clinical need, showing that unidentified vanishing twins caused a significant proportion (up to 15%) of false positive NIPT results.1, 2* These false positives lead to unwanted invasive procedures."
Unidentified vanishing twin pregnancies can also lead to fetal sex prediction errors if the vanishing twin is male and the remaining twin is female. Panorama solves that problem by leveraging a unique SNP-based technology (single-nucleotide polymorphisms) to recognize the presence of additional DNA signatures, thereby eliminating the error rates associated with vanishing twins. This helps avoid unnecessary invasive procedures and improve patient safety.
Triploidy refers to a fetus with an extra set of chromosomes (three copies of each chromosome). "Identification of triploid pregnancies is beneficial because of the substantial clinical implications for the mother," Dr. Gross continued. Triploidy occurs in roughly 1 out of 2,000 pregnancies at 12 weeks gestation, and it is known to cause severe fetal abnormalities, elevated risks for spontaneous abortion, pre-eclampsia, hemorrhaging, molar placentas, and choriocarcinoma, a form of cancer that occurs in the uterus. Early detection allows for necessary medical attention and clinical care for the mother. This was the second publication demonstrating Panorama's ability to detect triploidy. 3
The study, entitled Detection of triploid, molar, and vanishing-twin pregnancies by a single-nucleotide polymorphism-based noninvasive prenatal test by lead author Kirsten J. Curnow, PhD, reported on 30,795 consecutive clinical cases. It can be found online at www.ajog.org.
1Futch T, Spinosa J, Bhatt S, de Feo E, Rava RP, Sehnert AJ. Initial clinical laboratory experience in noninvasive prenatal testing for fetal aneuploidy from maternal plasma DNA samples. Prenat Diagn 2013;33:569-74
2Porreco RP, Garite TJ, Maurel K, et al. Noninvasive prenatal screening for fetal trisomies 21, 18, 13 and the common sex chromosome aneuploidies from maternal blood using massively parallel genomic sequencing of DNA. Am J Obstet Gynecol 2014
3Nicolaides KH, Syngelaki A, Gil MD, Quezada MS, Zinevich Y. Prenatal Detection of Fetal Triploidy from Cell-Free DNA Testing in Maternal Blood. Fetal Diagn Ther 2014;35:212-7
About the Panorama™ Prenatal Screening Test
Panorama is a safe and highly accurate non-invasive prenatal test (NIPT) that screens for common genetic diseases. Panorama is the only NIPT that uses Single-Nucleotide Polymorphisms (SNPs) to differentiate between and analyze both the maternal and fetal DNA. Through a simple blood draw that can be performed in a doctor's office, Panorama can screen for chromosomal abnormalities as early as 9 weeks gestation. Additionally, the test can determine the baby's gender, and results are provided to the clinician usually within 7-10 calendar days.
Natera is a genetic testing company that develops and commercializes non-invasive methods for analyzing DNA. The mission of the company is to help families diagnose and manage genetic disease. In pursuit of that mission, Natera operates a CAP-accredited laboratory certified under the Clinical Laboratory Improvement Amendments (CLIA) in San Carlos, Calif., currently offering a host of preconception and prenatal genetic testing services primarily to OBGYN physicians and in-vitro fertilization centers. In 2013, the company launched Panorama™, a safe, simple test for pregnant women that screens for the most common chromosomal anomalies in a fetus as early as nine weeks of gestation. Tests developed by Natera have not been cleared or approved by the U.S. Food and Drug Administration (FDA). For more information, visit www.natera.com.
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Michael Hromadik, 858-442-2215
SOURCE Natera, Inc.