Pregnant woman taking picture with her partner

Test Indications

This screening test is intended for patients at 10 weeks or greater gestation who meet any of the following criteria:

  • Advanced maternal age (≥35 years at delivery)
  • Positive serum screen
  • Abnormal ultrasound
  • History suggestive of increased risk for T21, T18, T13, or sex chromosome aneuploidy

Expansion into Twin Pregnancies

Natris™ has been expanded to include the option to test for Down syndrome, Trisomy 18 (Edwards Syndrome), and Trisomy 13 (Patau syndrome) in both monozygotic and dizygotic twin pregnancies. An option for the presence of the Y chromosome can be ordered for twins as well.


Down syndrome

Observed Sensitivity
Observed Specificity

Trisomy 18 (Edwards Syndrome)

Observed Sensitivity
Observed Specificity

Trisomy 13 (Patau syndrome)

Observed Sensitivity
Observed Specificity

Sex Chromosome Detection

Natris can also detect sex chromosome aneuploidies in singleton pregnancies – at no additional cost.

  • Monosomy X (Turner syndrome)
  • XXX (Triple X)
  • XXY (Klinefelter syndrome)
  • XYY (Jacobs syndrome)
  • Fetal sex (XX or XY) – aids in risk stratification of X-linked disorders such as hemophilia


XX (female)


XY (male)


MX (Turner syndrome)


Natris™ Plus – Responsibly Expanding the Accurate, Reliable, And Relevant Natris

Taking a deeper approach to the science of genomic sequencing, Natris™ Plus, which tests for microdeletions, provides a clearer picture of chromosomal health—detecting even small abnormalities with a high degree of accuracy and reproducibility. Natris™ Plus has been validated on actual clinical and analytical samples. Its optimized algorithm addresses the complexities of specific chromosomal regions to provide accurate answers about the loss of genetic material. The result is better overall performance, including a lower false positive rate and the lowest test failure rate in the industry.

What Is Included In Natris Plus?

The Natris™ Plus for singleton pregnancies tests for chromosomes 21, 18, 13 and additional tests options as shown below:

  • Select microdeletions such as 1p36 deletion, 4p- (Wolf-Hirschhorn syndrome), 5p- (cri-du-chat syndrome), 15q11.2 (Prader-Willi syndrome/Angelman syndrome), and 22q11.2 deletion (DiGeorge syndrome).
    • Sex chromosome aneuploidies (monosomy X, XXX, XXY, and XYY) are included if requested; fetal sex (XX or XY) will be reported if no sex chromosome aneuploidy is detected.
  • Aneuploidy (trisomy) of all chromosomes, including sex chromosome aneuploidies.

Natris™ Plus identifies six important genetic syndromes:

Disorder Incidence Clinical Features (may include but not limited to)
22q11.2 syndrome (DiGeorge syndrome, velocardiofacial syndrome) 1 in 4,000 Learning problems, congenital heart defects, palatal abnormalities
1p36 deletion syndrome 1 in 4,000 to 1 in 10,000 Characteristic craniofacial features, intellectual disability, seizures, brain and heart defects
Angelman syndrome/Prader-Willi syndrome (15q11.2 deletion syndrome) Angelman syndrome: 1 in 12,000

Prader-Willi syndrome: 1 in 10,000 to 1 in 25,000

Angelman syndrome: Intellectual disability, speech impairment, seizures

Prader-Willi syndrome: Hypotonia, morbid obesity, delayed motor and language skills, intellectual disability, hypogonadism

Cri du chat syndrome
 1 in 20,000 to 1 in 50,000 Intellectual disability, speech delay, cat-like-cry
Wolf-Hirschhorn syndrome (4p-syndrome)  1 in 50,000 Growth deficiency, hypotonia, craniofacial features, intellectual disability, heart and brain abnormalities

Test Results

Turn around time: Results can be expected 5-7 business days from the time the sample is received at the laboratory.

Results from Natris™ Plus are reported as “Positive: Aneuploidy Detected” or “Negative: No Aneuploidy Detected.” Results for chromosomes 21, 18, 13, X, and Y will continue to be reported individually. Results for the remaining chromosomes are reported collectively. A specific chromosomal aneuploidy will be reported in the event of a “Positive: Aneuploidy Detected” result. Results for a positive microdeletion syndrome will be reported as “Abnormality Detected.”

Click here to learn more about why Eurofins NTD Genetics has been the laboratory to trust for over 30 years.

Learn More

Leave the billing worries to us! NTD Genetics works hard to ensure that the billing process is simple and easy for your patients.

Interested in sending samples?

We can help you get started!

Contact Us for More Information