Monday, October 17, 2011

31 for 21: Day 17 ~ Prenatal Diagnosis

Just recently, a new test has become available in the United States. It is a non-invasive blood test which can do more than just screen for a possible genetic anomaly. It can virtually diagnosis or exclude diagnosis of T21 with a very high rate of accuracy. AND it's available as early as 10 weeks into the pregnancy.

Prior to the release of this blood test, a blood screening test was available in the first trimester and IF the results came back abnormal, then further testing could be pursued via CVS (chorionic villi sampling) or amniocentesis. The problem is that both of these tests are invasive, posing a risk, albeit a small one, of causing miscarriage. Also, the tests could only be performed within certain time frames; once the window of opportunity was missed, it was closed forever.

In many cases, women who decide they would not terminate a pregnancy for a positive diagnosis of T21 don't pursue the more conclusive tests because there's no point in putting the fetus at risk when they wouldn't do anything differently even if a diagnosis is made. The problem is that some women are left to wonder and worry when their screenings come back positive for a possible problem and they don't get a definitive answer until the baby is born. Stress like that is not good for mom-to-be or the baby-to-be.

Now that this new test is available, some women may be able to avoid the pitfalls of current testing, without putting the fetus at risk. But there is a downside to all of this. Recent surveys have shown that there is a very high rate of life satisfaction among parents of, siblings of and individuals with T21. Many of these people received a diagnosis post-natal (after birth). If more of these families had known of the diagnosis prior to entering the second trimester of pregnancy, would they have opted to terminate the pregnancy out of fear? It's certainly a question worth entertaining. Current information reflects a termination rate of about 90% of pregnancies in which the fetus is diagnosed with T21. With this new testing available, is it possible that we'll see an increase in that rate? It's a scary thought to those who have children with T21.

Considering that T21 is the most common genetic disorder among living people, the interest in finding sound medical help for children with this disorder seems minimal compared to the research being pursued for other medical issues. What impact might this new test have on that research? What if the possibility exists (because of this test) that future generations of people with T21 might be virtually eliminated? What does that mean for those who are already here?

Pharmacological research is typically a for-profit venture. If there's no money to be had in finding a "cure" for certain symptoms or conditions, then the companies running the show have substantially less interest in funding research. If the population of individuals with T21 diminishes in the future, then what happens to interest in research to better the lives of those individuals who are around? It's scary to think about what might be...

Ask just about any pregnant woman what she hopes for her child and more than likely you'll hear, "as long as it's healthy..." The truth is that the majority of people plan for  an "ideal" child and have a vision of what that child's life might be like in an "ideal" future. Unfortunately life doesn't usually work that way. As a species, we have variations in our genetic makeup. Some variations are slight and allow an individual to conform to the cuturally accepted norms without issue. Other variations are condemned as undesirable and people seek to avoid them.

I can certainly understand this; I think in some ways, it's built into our DNA just as in other animals. If given the option, I never would have asked for my child to have T21 any more than someone might request to have a child who is missing limbs or has a cleft palate or develop autism. But, we are human and can think beyond the encoding in our DNA. These variations exist and the people with these conditions have value just as any other member of society. With the availability of newer and better testing to "improve" prenatal diagnosis, I believe it's more important than ever to understand and embrace the differences in us all and recognize that there is value in all life, not just that viewed as ideal form of it.

Now that my little guy is here with us and we're learning just who he is, underneath the changes made by that extra chromosome, we're seeing affirmation that he really isn't all that different from the rest of us. He's got 24 chromosomes from Mommy (probably) and 23 chromosomes from Daddy and he looks a heck of a lot like his sister and behaves a lot like his brothers. But he's also his own unique person and I can't wait to find out more about him. I'm going to help him in any way I can to reduce the effect that having T21 has on his body and mind, but at less than 4 months into this journey with Levi, I can honestly say that I wouldn't change who he is for the world.

Now, after my SUPER long essay (kudos to you if you stuck around to read the WHOLE thing)...I'd like to share the following information provided by  Brian Skotko, MD, MPP, clinical genetics fellow at Children's Hospital Boston

DATA FROM THE NEW STUDY by PALOMAKI ET AL.
- a "positive" test means that there is a 98.6% chance that the fetus really does have trisomy 21
- a "negative" test means that there is a 99.8% chance that the fetus really does not have trisomy 21
- 98.6% of fetuses with trisomy 21 will be correctly identified as having trisomy 21
- 99.8% of fetuses without trisomy 21 will be correctly identified as not having trisomy 21
- Approximately 0.8% of samples did not have a result one way or another (as they did not meet certain technical and quality standards)
- The company also did a statistical adjustment, that could change the percentages above to 99.5%, 99.9%, 99.1%, and 99.9% respectively.
- Approximately 2.5% of the samples were rejected at the beginning because of inadequate amount (meaning that the results could not be run)
DETAILS OF TEST
- available early as 10 weeks of gestation
- about 10 day turnaround
- $1500-2000 to insurers
- max person will have to pay is $235 out of pocket
- this is ONLY a test for trisomy 21 and not for other forms of Down syndrome (i.e., translocation Down syndrome or mosaic Down syndrome)
- Therefore, a "negative" result could still mean that a fetus has Down syndrome (just one of the other forms)
- A "negative" result could still mean that the fetus has trisomy 18, trisomy 13, or other genetic conditions picked up by CVS or amnio
ELIGIBLE PERSONS
- must live or travel to one of 20 select cities
- must be >35 yo OR
- must have abnormal ultrasound finding OR
- must have a family or personal history of DS or other aneuploidy OR
- must have a serum "positive" screen


PRESS COVERAGE SO FAR


RESPONSES TO SHARE WITH MEDIA AND OTHERS

If you are in contact with the media, please feel free to share with them the following press releases and position statements. If the media have any questions, please direct them to Julie Cevallos at the NDSS (jcevallos@ndss.org).

National study on life with Down syndrome (Skotko, Levine, Goldstein)
Press release: http://www.brianskotko.com/images/stories/Files/skotko%20ajmg%20press%20release.pdf
Physicians sometimes deliver inaccurate, incomplete, and offensive information about Down syndrome
Position Statement from the National Down Syndrome Society on Criteria that will be used to Evaluate Companies

If you made it this far, thank you for sticking around and I promise far less text tomorrow....(well, later today since it's officially after midnight here now...)

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