Read More: Lineagen uses a painless cheek swab for sample collection
In most cases, when a provider orders a genetic test, blood collection is the gold standard in genetic testing. It's common practice to use blood samples and it has been for a long time.
However, many families aren't getting their child tested because blood draw just isn't an option for them. We've heard from many providers that they've stopped ordering certain tests because families refuse to put their child through a blood draw.
Blood draws can be traumatic for children
Blood draws can be particularly traumatic for children with developmental disabilities who have certain hypersensitivities. With Lineagen's FirstStepDx PLUS testing, we have elected to validate a buccal cheek swab DNA collection and use that rather than blood collection for our CMA.
We've chosen to use the buccal swab for three main reasons:
Ease of collection
The first is the ease of collection. No one enjoys having their blood drawn. And a cheek swab is much more familiar territory for a child. Parents will often help with the collection of the DNA and incorporated collection with a daily routine such as pretending to brush their teeth.
That's something the child isn't threatened by. It's something mom or dad can easily help with in the office. It's much easier to use and it can be done right there in the evaluation room and the family doesn't have to go halfway across the medical campus or down the road to a phlebotomy station.
Cheek swab samples are much more stable than blood
In addition to ease of collection, the DNA collected from a cheek swab can be stable for much longer than a blood draw. Clinicians ordering a blood draw for a patient need to worry about numerous factors:
- Is it shipped overnight?
- Does the sample have to be on ice or dry ice?
- What's the temperature outside?
- Will there be potential shipment delays?
Cheek swabs are stable for two months at room temperature
With the DNA cheek swab used by Lineagen, the stability of that sample lasts up to two months (60 days). Room temperature is the best way to ship and store the sample and provides us with flexibility so that we can do the necessary work with the insurance and contact the family. A blood sample requires refrigeration and will only last a few days. There is not the time restriction that we would have if we were handling a blood sample.
The cheek swab is technically better than blood for this type of genetic testing
The third reason why the cheek swab is preferred over the blood draw for our CMA service is because the results are actually technically better from the cheek swab. An example is the detection rates for mosaicism and mosaic syndromes such as mosaic trisomy 21 or mosaic Turner's syndrome. Lineagen has reported a result in which we found 20% mosaic trisomy 21 in the buccal sample while the blood sample from the same individual only showed 5% mosaicism1
If only the blood was tested in this individual, that diagnosis would've been missed. And of course having a diagnosis of trisomy 21 is very critical for a provider to know so that the child can be put on a special healthcare supervision plan to monitor for the risks associated with Down syndrome.
1. Data on file