Illumina test London with GP advice: NO NEED to pay for an ultrasound if one is not required.
After careful consideration, we have changed our noninvasive prenatal test (NIPT) from Harmony to Illumina VeriSeq® NIPT solution V2 assay deemed superior by our team of skilled doctors.
What the Illumina VeriSeq NIPT solution V2 screens for
The Illumina blood test gives an analyses of cell-free DNA (cffDNA) circulating in a pregnant mother’s blood.
This provides one of the most accurate screening approaches to estimate the risk of a common chromosomal abnormality (known as a trisomy) in a foetus. A trisomy occurs when there are three copies of a particular chromosome instead of the usual two.
The Illumina NIPT screens for conditions like Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13). It can also determine the gender of your child.
The test can be performed as early as 10 weeks into a pregnancy. As this is a simple blood draw from the pregnant mother, it poses no risk or harm to the foetus.
Why do our doctors rate the Illumina VeriSeq superior to the Harmony?
- Better detection rates for all three trisomy types (>99%). Harmony is 99% for trisomy 21; 97% for trisomy 18 and 93% for trisomy 13.
- Only 1% of samples will fail to process. Harmony has a 4% failure rate.
- Shorter turnaround times – usually three to four working days. Harmony takes five to seven working days.
- Positive Prediction Rate (PPV) same as the Harmony test.
- The Illumina test originates from an American biotechnology company which have partnered with the largest NIPT laboratory in the UK, TDL Genetics, for analysis. It is one of the only labs with UKAS accreditation for NIPT testing (same as Harmony test).
Cost of the Illumina NIPT test
| Procedure:Illumina VeriSeq Blood Test Only (Includes discussion with your doctor and signing your consent forms) [You have to be AT LEAST 10 weeks’ gestational age – we will need ultrasound scan proof to proceed with your blood test] Price: £375 (£15 Surcharge for weekend appointment) |
We encourage you to have an ultrasound scan immediately prior to the Illumina VeriSeq blood test. Missed miscarriages commonly occur before 12 weeks’ gestation and you may not want the heartache of the Illumina test result if this might be the case. We are unable to provide any refunds.
Eligibility criteria
To be eligible for the Illumina VeriSeq blood test, patients MUST BE at least 10 weeks’ gestational age.
They can have a singleton or twin pregnancy resulting from natural conception or IVF using your own egg or that of a donor.
Foetal sexing is also now available for twin pregnancies, but patients who are pregnant with more than one foetus, are NOT eligible for the Illumina prenatal test with X and Y analysis.
Repeat testing policy
In the very rare instance (less than 1% chance) that the laboratory cannot find enough foetal cell-free DNA in your blood to perform an analysis, we will repeat your test free of charge.
HOWEVER, if we are unable to find enough cell-free DNA the second time round, the lab will NOT repeat the test for a third time. In this case, you will be refunded £255. The GP Surgery will retain the remainder as an administrative fee.
For the above reason, please ensure you have your Nuchal scan and NT blood tests from your NHS hospital and don’t rely on definitely getting a result from your Illumina test. Furthermore, the positive predictive value (see below) is based on your Nuchal/ NT blood test result, so it is very important for you to have it done.
You are paying for Trisomy 21/18/13 testing. The laboratory offers foetal sex testing and the sex chromosome aneuploidy panel testing as additional complimentary investigations. Hence if results from the latter two are inconclusive, they will not repeat them for you free of charge.
Conditions tested for with the Illumina VeriSeq blood test
Trisomy 21 (Down Syndrome) – This may be associated with moderate to severe intellectual disabilities and may cause other organ defects.
Trisomy 18 (Edwards Syndrome) and Trisomy 13 (Patau Syndrome) – This is associated with a high rate of miscarriage. Babies who do survive, are born with severe brain abnormalities, as well as other birth defects.
Sex chromosome analysis – The sex chromosomes (X and Y) determine if we are male or female. The Illumina VeriSeq blood test evaluates X and Y chromosome sequences, providing information on foetal sex and sex chromosome aneuploidy.
The Illumina VeriSeq blood test is not intended nor validated for the diagnosis or detection of mosaicism, partial trisomy, or translocations.
Accuracy of results
The Illumina VeriSeq prenatal blood test has a very high accuracy rate in the detection of foetuses with Trisomy 21, Trisomy 18 and Trisomy 13. Please be aware that some X and Y chromosomal abnormalities may however have a much lower accuracy rate of detection.
X and Y analysis of NIPT has a high diagnostic accuracy for foetal sex. If Y chromosome DNA is detected, the foetus is male. If no Y chromosome DNA is detected, the foetus is female.
It is important to note that if the test results show a high risk of trisomy 21, 18 or 13 or sex chromosome conditions, it does not automatically mean that the foetus definitely has one of these conditions – but it is highly likely.
Hence, in the event of a “high risk” (or positive) result, we would recommend discussing follow-up testing via an invasive method (such as amniocentesis) with your obstetrician.
Similarly, a “low risk” (or negative) result does not automatically mean the foetus does not have the above conditions. However, there is always a marginal risk that not all trisomy foetuses will be detected.
It is important to continue with all your normal scans and to interpret their readings in context of your risk factors and family history.
PPV: What to know
The Advertising Standards Authority (ASA) has made a ruling on false advertising for prenatal testing. TDL Genetics have provided the Positive Predictive Value (PPV) figures required and these are AVAILABLE HERE.
PPV – the probability that a positive test result is a true positive – depends on both test performance and the prevalence of the condition in a given population.
The population-based PPV in the table was determined in a large prospective study of a first trimester routine-screening population. PPV will be higher in high-risk populations.
Clinical factors, such as family history and results of other screenings, may influence the PPV for an individual patient.
Special circumstances to consider
If you weigh more than 100kg, it is recommended you wait until you are at least in your 20 weeks pregnancy to have the Illumina VeriSeq test.
Ineligibilty criteria
You will NOT be eligible for the Illumina VeriSeq test if:
- You have received an organ transplant.
- You have received a bone marrow transplant.
- You have metastatic cancer.
- You have a vanishing twin pregnancy: The release of cell-free DNA from the trophoblast of the perished embryo leads to inaccurate results.
How long before I get my results?
Approximately three to four days. Please keep in mind that we are a third party using TDL Genetics to analyse your blood test. In the event of any delay (which rarely occur), we request that you contact them directly to discuss your concerns.
The way forward: What happens if the result is positive?
Should the test produce an unfavourable result, appropriate counselling will be provided regarding the PPV.
It is important to note that the only way to be 100% sure, will be to have an amniocentesis if there is no indication of a repeat of the NIPT test.
Your NHS obstetrician will offer you an amniocentesis which – due to safety reasons – can only be done after 16 weeks’ gestation.
Amniocentesis involves removing and testing a small sample of cells from the fluid that surrounds the foetus / baby in the uterus.
For further understanding and more useful information on the Illumina VeriSeq NIPT solution V2 assay, click HERE.