Down syndrome is caused by a chromosomal aberration that comes about during formation of an egg, not a mutation. It's not possible to detect it by screening the parents' DNA.
But it is possible to detect by screening the embryo's DNA, which is currently happening. Still I don't think this technology will reach universal adoption within the next 50 years.
You're correct, but so is the person you replied to; they wrote their comment confusingly, though.
PGT-A testing is very common in IVF and will catch Down Syndrome. Essentially no births from IVF (a growing percentage of all births) have Down Syndrome.
As you mention, this testing is done after an embryo has been created.
It's not just amusing (and for some, uncomfortable) terminology. Pregnancy stimulates the mother's immune system in ways normally associated with fighting a parasite, and the fetus defends itself using techniques that successful parasites use.
"Embryo implantation sets off a process that ultimately turns off a key pathway required for the immune system to attack foreign bodies. As a result, immune cells are never recruited to the site of implantation and therefore cannot harm the developing fetus."
I get it, based on a variety of medical phenomena, you can draw parallels between an unborn baby and a parasite. If thats your point, then fine, fair enough.
If you seek to use this analysis to push a political agenda, then I am having trouble differentiating the morality between that and slave owners pointing to the shape of skulls based on race. Your explanation is an analogy, parasites dont grow up to eventually provide care for the host, it doesnt sound scientificially accurate to call a baby a parasite based on some of the characteristics. Further, calling a baby a parasite, or anyone for that matter, is an attempt to dehumanize them; dehumanization has been followed by violence in a number of horrific tragedies, but the violence is committed by people who find it justified, because whoever they are killing aren't really people.
I didnt, and I knew the answer ahead of time. I think thats an insane way of thinking about things, barbaric and cruel, but I would rather parent spells it out and I leave it at that. Its the internet, people can and should say what they really think, im just helping parent get there.
I said exactly what I meant to say. I got there just fine on my own like the big boy I am.
I've had many a conversation with women that have decided to not have kids. This is where I first heard of a fetus referred to as a parasite. I found it quite humorous. It's their body after all*, and if that's how they think of having some life form growing inside their body, I'm here for it.
While I'm terrible at predicting the future, I find this hard to believe. I think screening your DNA is something maybe upper/middle class parents might do. I do not believe it is being done by those that cannot afford it.
As the cost of doing it comes down, i would expect it to be offered more widely. I don't know if it will ever be cheap enough to offer to all prospective parents.
Oddly, the cost of doing genetic tests does not scale at all linearly:
Scanning for Downs syndrome is default in Denmark where I live. It makes a lot of sense.
You will get a probably of Downs syndrome. No one is aborting your baby - you can take an informed decision yourself.
After birth a blood test is used for scanning for 25 rare known issues.
> No one is aborting your baby - you can take an informed decision yourself.
Of course, this is exactly the point of Gattaca: you won't be "forced" to do it, but you and your child will be punished for making the socially unacceptable "choice".
The genetic tests were already down to $1,000 retail per parent a decade ago at the company I worked at and it tested for hundreds of hereditary diseases. Those base tests are even cheaper now thanks to microarrays and the mid/high end has moved up to full genome sequencing.
It won't be long before it's dirt cheap and standard in most countries, especially as the Affymetrix/Illumina patents expire and the genechips get commoditized.
In the UK, the NHS runs scans and blood tests as standard procedure at around 12 weeks, which can indicate any risk of something like Downs syndrome. You can then be referred for amniocentesis if necessary, all free at point of service. I'm sure many other European countries are similar.
I went through IVF and I can't make babies that have my particular mutation in them (even though it's not apparently disease causing and unknown to science) unless I sign a shit ton of paperwork.
So, we have to go with the Gattaca-y genomincally perfect embryos. Or conceive in the back of a car or something.
There are genetic screens for a few congenital disorders. A friend’s daughter was genetically screened for galactosemia and by catching it they almost certainly helped her have a normal life.
But since Gattaca was released, we’ve just continued to learn that it’s likely impossible to predict the full capability of a person from only DNA. There are too many variables in how genes are expressed, and the social context in which each person finds themselves.
That said, the real story of Gattaca is unjustified discrimination, and there are already plenty of technologies for that. So in that sense I think you’re right that it’s already among us. Just as it was in 1997… Gattaca is a pretty transparent allegory.
It's estimated that there won't be anyone with Down syndrome in a few decades.
Estimated by who? Perhaps in the places where parents have enough access to enough prenatal health care and/or enough disposable income for the test and the procedure. Or the places where legislatures aren't trying to make terminating a pregnancy under any circumstance murder. This will clearly come as a great surprise to you, but those conditions cover a very large percentage of humans.
So, no, from a practical standpoint genetic diseases probably aren't going to magically go away any time soon no matter what technology exists to identify them.
In this tough world, bringing in a child with Down syndrome is committing to their lifelong care and carefully planning who will take over the job of caring for them when you die. Don’t do it.