Since NIPT testing first became available in early 2013, there have been changes to test methodologies and the emergence of new evidence about performance from recent studies. After reviewing the currently available forms of NIPT, we conclude that the Harmony™ Prenatal Test offers the best attributes of quality, reproducibility and consistency that will bring significant benefits to clinicians and the patients they care for.
A Higher Standard of Care in Trisomy Testing
While traditional blood tests can miss as many as 15% of Down syndrome cases in pregnant women, Harmony’s DNA-based technology accurately identifies more than 99% of cases.
Harmony is an accurate and reliable test that specifically targets the DNA in chromosomes 21, 18 and 13. These chromosomes account for the most common trisomies that occur in babies born to women of any age, when no other risk factors are known.
As early as 10 weeks, the Harmony Prenatal Test assesses the risk of trisomy 21 with unsurpassed accuracy in pregnant women, of any age or risk. In the first and only prospective blinded study of its kind published in the New England Journal of Medicine, the Harmony Prenatal Test proved superior to traditional first trimester combined screening for both detection rate and false-positive rate.
Superior Quality Control
The Harmony test incorporates extensive quality controls. These controls include precise measurement of the amount of the developing baby’s DNA in each sample, to ensure that there is enough DNA present to return a reliable result. While it may seem surprising, not all DNA-based genetic tests take the care to measure this basic information.
The Harmony Prenatal Test has unsurpassed accuracy, bringing clarity to genetic testing for common trisomies.
Conventional prenatal screening methods using serum proteins and ultrasound have higher false-positive rates, causing healthcare providers and their patients unnecessary worry and additional invasive testing.
- In blinded clinical trials, Harmony correctly identified over 99% of cases of trisomy 21
- Conventional screening tests can miss 15% or more of trisomy 21 cases
Internationally Validated Accuracy
- Harmony has a less than 0.1% false-positive rate
- This means fewer than 1 in 1000 Harmony tests yields a false-positive result
- With conventional screening, as many as 1 in 20 women will receive a false-positive result
Harmony has one of the highest positive predictive values (PPV*) for trisomy 21 of any cell-free DNA-based trisomy 21 test.
Any Age or Risk Category
Harmony Prenatal Test is clinically validated for use in pregnant women, of any age or risk category, to assess the risk of fetal trisomies 21, 18 and 13.
- Harmony is the most broadly studied cell-free DNA-based maternal blood test
- Clinical studies in more than 23,000 women of all ages
- Over 500,000 pregnancies tested worldwide
Performed in Australia
Sonic Genetics now performs Harmony non-invasive prenatal testing in our Australian laboratory.
The Harmony Prenatal Test is widely recognized for its unsurpassed accuracy in assessing the risk of selected chromosomal abnormalities in pregnant women of any age or risk category. To date, Harmony has been performed on more than 500,000 patient samples through the Ariosa laboratory in the USA.
Testing in Australia has several benefits:
- Faster result delivery
- Lower price
- Testing performed to Australian testing standards – Sonic Genetics is the only Australian laboratory to have received accreditation from the National Association of Testing Authorities (NATA) for the Harmony Prenatal Test.
- Less chance of the sample going missing, or reducing in quality due to long distances and overseas flights
As part of our service, patients based in Australia that have received a result indicating a raised likelihood of a fetal chromosomal abnormality and have paid their local Sonic Healthcare pathology provider for this test are able to access telephone-based genetic counselling free of charge. Please note that this counselling is limited to addressing informational and psychological matters relating to this result. The genetic counsellor does not manage amniocentesis or other investigations; the patient’s doctor remains responsible for the subsequent management of the pregnancy. Please note that Sonic Healthcare provides comprehensive no-gap cytogenetics services for invasive prenatal testing.
To access this genetic counselling service, the patient’s doctor should fax or email a medical referral for the patient to us. We will confirm receipt of the referral, and forward it to an independent accredited genetic counsellor who will contact the patient directly within three business days. The counsellor will send a report direct to the requesting doctor after the counselling session (or if the patient declines the offer).
Independent genetic counselling is available for all other tests and patients on a fee-for-service basis, please refer to www.sonicgenetics.com.au/doctors/resources for a list of services or contact us.
A Unique, Targeted Technology
Harmony uses a targeted technological approach to DNA assessment—focusing on analyzing only the specific chromosomes of interest and the precise measurement of fetal DNA using SNPs (single nucleotide polymorphisms) to achieve greater accuracy.
1. Accurate Measurement of Fetal Fraction
The Harmony methodology incorporates extensive quality controls:
- Single nucleotide polymorphism (SNP) analysis is used to precisely quantify cfDNA and determine the fetal DNA contribution in a sample
- Harmony also incorporates the fetal DNA measurement into its risk assessment using FORTE, a proprietary algorithm, to more clearly distinguish high and low risk results
Fetal fraction assessment is particularly important at low fetal fractions, where other methodologies have demonstrated a larger number of discordant results.
These important controls are not included at all in some cfDNA-based trisomy tests, increasing the risk of both false-positive and false-negative results.
2. Depth of Analysis
With random sequencing, the majority of sequence tags do not originate from the chromosomes of interest. For example, only 1-2% of tags are expected to originate from chromosome 21 (chromosome 21 represents 1-2% of the genome).
Harmony’s unique DANSR assay with microarray quantification allows targeted, deeper analysis of chromosome 21 and other chromosomes of interest, providing clear answers to the questions that matter.