The clinical performance of the IONA® NIPT Workflow is assessed as part of the development process prior to product launch. Post-launch, as required by the medical device regulation and for our quality system we monitor performance via a process called ‘post-market surveillance’. Post-market surveillance is a set of activities conducted by manufacturers to collect and evaluate experience gained from medical devices that have been placed on the market. It is done with the intention of ensuring we can identify any trends that suggest the need to take any action e.g. withdrawing a faulty batch from the market.
The data from both the initial validation work and post-market surveillance activities is provided below.
| IONA® Nx trisomy validation studyA | ||
|---|---|---|
| Sensitivity | Specificity | |
| Trisomy 21 |
>99.99% |
>99.99% |
| Trisomy 18 |
>99.99% |
>99.99% |
| Trisomy 13 |
>99.99% |
>99.99% |
A Validation performance has been demonstrated by evaluating 472 clinical samples from singleton and monochorionic/dichorionic twin pregnancies and comparing them to a reference result. Reference results include an amniocentesis or chorionic villus sample (CVS) sample or a birth outcome.
| IONA® Nx additional validation studyB | ||
|
|
Sensitivity |
Specificity |
|
XO |
>99.99% |
>99.99% |
|
XXY |
>99.99% |
99.5% |
|
XYY |
N/A |
>99.99% |
|
XXX |
>99.99% |
>99.99% |
|
Autosomal Aneuploidy |
>99.9% |
99.3% |
|
Monosomy |
N/A |
>99.9% |
BValidation performance has been demonstrated by evaluating 443 clinical samples from and comparing them to a reference result. Reference results include an amniocentesis or chorionic villus sample (CVS),or a birth outcome..
This has been demonstrated using the IONA® Nx cfDNA Library Preparation DX kit and the IONA® analysis software version 2.0.2. Data held on file by Yourgene Health Plc.
The above data for IONA® Nx trisomy validationA is from a sample set that includes singleton, monochorionic and dichorionic twin pregnancies. Please note that in dichorionic twins, the test sensitivity for Trisomy 21 has been observed in our Genomic Services laboratory to be reduced from >99% to about 95%. The IONA® Analysis Software uses a specific proprietary algorithm iteration for dichorionic twins, but it will not distinguish which twin is high risk.
Please note that the additional validation studyB results do not include data from dichorionic pregnancies. Therefore, sex chromosomal aneuploidy and autosomal aneuploidy analysis have not been validated for application in dichorionic twins at this time.
Fetal sex determination is not available for twins.
Post-Market Surveillance Data
IONA® Nx NIPT Workflow performance following post-market surveillance of pregnancies. Please note data is not available at this time for additional conditions detectable by the test other than the trisomies listed below. Data is also not yet available as a breakdown of single, monochorionic and dichorionic pregnancies. Please note that in dichorionic twins, post market surveillance data specifically from our Genomic Services laboratory has shown sensitivity for Trisomy 21 to be reduced from >99% to about 95%.
We will update this page regularly as more information becomes available.
|
The IONA® Nx test |
Sensitivity (Detection or True Positive Rate) |
False Negative Rate (FNR) |
Specificity (True Negative Rate) |
False Positive Rate (FPR) |
Positive predictive value (PPV) |
Negative predictive value (NPV) |
|
The proportion of truly affected pregnancies that screen positive. |
The proportion of pregnancies that have the syndrome but have screened negative. |
The proportion of truly unaffected pregnancies that screen negative. |
The proportion of pregnancies that do not have the syndrome, but have screened positive. |
The likelihood that a screened positive pregnancy is truly affected with a condition. |
The likelihood that a screened negative pregnancy is truly unaffected with the condition. |
|
|
Trisomy 21 Down's sydnrome (201 / 9,575) |
>99.99% (200/200) |
<0.001% (0/200) |
99.97% (9,374/9,375) |
0.01% (1/9,375) |
99.50% (200/201) |
>99.99% (9,374/(9,375-201) |
|
Trisomy 18 Edwards' syndrome (61 / 9,575) |
98.33% (59/60) |
1.67% (1/60) |
99.97% (9,513/9,515) |
0.02% (2/9,515) |
96.72% (59/61) |
99.99% (9,513/9,575-61)) |
|
Trisomy 13 Patau's syndrome (15 / 9,575) |
>99.99% (15/15) |
<0.001% (0/15) |
>99.99% (9,560, 9,560) |
<0.001% (0/9,560) |
>99.99% (15/15) |
>99.99% (9,560/(9,575-15)) |
|
What does it mean for the pregnancy? |
The high IONA® PPV implies that the false positive results are minimised (unaffected fetus tested positive); meaning less unnecessary diagnostic procedures are required. |
The high IONA® NPV implies that the false negative results are minimised (affected fetus tested negative), meaning fewer syndromes are being missed. |
Observed performances data is based on post-market surveillance of the IONA® Nx NIPT Workflow in over 9,575 pregnancies, from a population of women who are predominantly at a higher risk of having a fetus with Down's syndrome.
Performances are dependant of laboratories fully reporting discordant results to Yourgene Health Plc. From Data held on file by Yourgene Health. Correct as of 11th June 2021.