4 ms·

Is it true you can detect these sorts of thing before birth or is it still a shot in the dark?

by dmix 4y ago

cfu28 4y ago
A screen for Down's syndrome is routinely done at the end of the first trimester/start of the second trimester.
- GordonS 4y ago
  This is true, but that test is inaccurate, and only provides odds of having a baby with Down's, for example "you have a 3500:1 chance of having a baby with Down's Syndrome".
  - cfu28 4y ago
    Right, but a positive screen is usually followed up with a more specific test (karyotype, cvs, amniocentesis) which can give a definitive diagnosis. Also the screen has a sensitivity of 95% with a positive test indicating > 1/300 chance in Down’s syndrome, so the screening is not nearly THAT bad
    - GordonS 4y ago
      > Right, but a positive screen is usually followed up with a more specific test (karyotype, cvs, amniocentesis) which can give a definitive diagnosis. I was thinking more of false negatives than positives, but reading it back, there was no way for you to know that from what I wrote! The test for our daughter came back negative (well, something like 3,000,000:1 chance of Down's), but she did actually have Down's. Later, talking with other parents of kids with Down's, multiple had had similar odds, some even crazier (and in a small country with <50k births each year).
MontyCarloHall 4y ago
Yes, extremely reliably, to the degree that Down syndrome has almost disappeared in societies with widespread prenatal screening [0]. [0] https://www.cbsnews.com/amp/news/down-syndrome-iceland/ https://www.cbsnews.com/amp/news/down-syndrome-iceland/
d136o 4y ago
First of all, I want to be respectful of the parent comment, much much respect for all the hard work that it must be. To your question, prenatal screening is a thing, but maybe non-invasive techniques (that don’t risk miscarriage) are newer. I don’t know how widely recommended they are throughout the country (US) or world, but they were prescribed for our kiddo born San Francisco this year. They seem to stagger the tests, so that the less invasive ones are used at first, and then the more invasive procedures are recommended if there is information that would indicate an increased risk of whatever condition. See for example: https://www.ucsfhealth.org/education/prenatal-testing-for-down-syndrome https://www.ucsfhealth.org/education/prenatal-testing-for-do... Some might say that these tests are being over used… it’s very personal imo.
- CrHn3 4y ago
  Non-Invasive Prenatal Testing (NIPT) was made available in the US in 2011. It’s highly sensitive for detecting down’s syndrome. Self pay is now 100-300 USD but a few years ago I think it was as much as 3000. It’s fully covered and encouraged for geriatric pregnancies, which are much more likely to have an extra copy of chromosome 21. The NIPT can screen for the sex of the baby earlier than it can be detected on a scan, so many women elect to have it done. The first trimester ultrasound is around 96% accurate at detection of down’s syndrome.
  - Waterluvian 4y ago
    We got this for free in Canada. My first kid had the soft positive marker for it in his first ultrasound (Interesting you say 96% because our doctors said it meant a 1 in 300 chance. Maybe we are talking about different things). So they sent us to Hamilton a week later for genetic screening. The geneticist walked us through the results and said that the tests are effectively negative and now his odds are something like 1 in 5000. This is all to say: indeed they have non-invasive tests and they’re very accessible.
    - jpollock 4y ago
      Without knowing the number of tests performed, you can both be correct. Theirs would be the false positive rate (FPR) or false negative rate (FNR), and yours would be an probability, which takes the FPR (or FNR) rate, the number of tests and the base incidence rate to arrive at 1/300, 1/5000. For example, in Canada, 1/750 of live born babies has Down's [2]. There are about 400,000 births every year in Canada [3]. So, there are 400,000 / 750 = 500 kids with Down's born every year. Assume the test has a FNR rate of 0, and a FPR of 5%. 400,000 * 0.05 + 500 = 20,500 children test positive Odds of positive test indicating Down's (5% FPR): 500/20,500 = 2.4% Not quite the 1/300, but as you said "soft marker", so maybe the FPR is higher for that, vs all the markers? To get to 1/300, the FPR rate on the marker would need to be 37.5%? The 1/5000 is (I believe) a change from a FPR rate to the FNR rate, since the second test is indicating that the disease _isn't_ present. 1/5000 would indicate a negative genetic test will miss one Down's diagnosis in a decade in Canada. Interestingly, it looks like the FRP increases with age, with it being 4% at age 30 (combined ultrasound/blood test)? [1] [1] https://pubmed.ncbi.nlm.nih.gov/11702835/ https://pubmed.ncbi.nlm.nih.gov/11702835/ [2] https://www.canada.ca/en/public-health/services/publications/healthy-living/down-syndrome-surveillance-2005-2013.html https://www.canada.ca/en/public-health/services/publications... [3] https://www.statista.com/statistics/443051/number-of-births-in-canada/ https://www.statista.com/statistics/443051/number-of-births-...
wraithgourd 4y ago
You do realize that before Allied Mastercomputer, her intelligence and yours are basically the same? The only difference is in how good you are to others.
- cercatrova 4y ago
  By that logic a bacterium and I are also basically intellectually the same before a superintelligence, in the Bostrom sense.
- overboard2 4y ago
  Why should the values of a superintelligence affect our own?
  - vintermann 4y ago
    It shouldn't, unless you derive your idea of worth from your intelligence, which you also shouldn't.
- astrange 4y ago
  You know that just because you’ve imagined something called a superintelligence doesn’t mean there is such a thing, right?
tomcam 4y ago
sacrosancty 4y ago
Worth noting that some mothers perfer not to test for it because there's an implication they'll decide to kill their baby if it's "defective" which they find horrible and unloving. Eugenics, basically.
GordonS 4y ago
Yes, there is now the NIPT test, which is something like 99% accurate, and involves taking blood from mother and extracting fetal DNA from it. It's more expensive than the older, inaccurate screening test, so here in the UK it isn't routinely offered to parents, or even explained to them. It's offered by private clinics though.

Is it true you can detect these sorts of thing before birth or is it still a shot in the dark?

by dmix 4y ago

Is it true you can detect these sorts of thing before birth or is it still a shot in the dark?

cfu28 4y ago

A screen for Down's syndrome is routinely done at the end of the first trimester/start of the second trimester.

GordonS 4y ago
This is true, but that test is inaccurate, and only provides odds of having a baby with Down's, for example "you have a 3500:1 chance of having a baby with Down's Syndrome".
- cfu28 4y ago
  Right, but a positive screen is usually followed up with a more specific test (karyotype, cvs, amniocentesis) which can give a definitive diagnosis. Also the screen has a sensitivity of 95% with a positive test indicating > 1/300 chance in Down’s syndrome, so the screening is not nearly THAT bad
  - GordonS 4y ago
    > Right, but a positive screen is usually followed up with a more specific test (karyotype, cvs, amniocentesis) which can give a definitive diagnosis. I was thinking more of false negatives than positives, but reading it back, there was no way for you to know that from what I wrote! The test for our daughter came back negative (well, something like 3,000,000:1 chance of Down's), but she did actually have Down's. Later, talking with other parents of kids with Down's, multiple had had similar odds, some even crazier (and in a small country with <50k births each year).

MontyCarloHall 4y ago

Yes, extremely reliably, to the degree that Down syndrome has almost disappeared in societies with widespread prenatal screening [0]. [0] https://www.cbsnews.com/amp/news/down-syndrome-iceland/ https://www.cbsnews.com/amp/news/down-syndrome-iceland/

d136o 4y ago

First of all, I want to be respectful of the parent comment, much much respect for all the hard work that it must be. To your question, prenatal screening is a thing, but maybe non-invasive techniques (that don’t risk miscarriage) are newer. I don’t know how widely recommended they are throughout the country (US) or world, but they were prescribed for our kiddo born San Francisco this year. They seem to stagger the tests, so that the less invasive ones are used at first, and then the more invasive procedures are recommended if there is information that would indicate an increased risk of whatever condition. See for example: https://www.ucsfhealth.org/education/prenatal-testing-for-down-syndrome https://www.ucsfhealth.org/education/prenatal-testing-for-do... Some might say that these tests are being over used… it’s very personal imo.

CrHn3 4y ago
Non-Invasive Prenatal Testing (NIPT) was made available in the US in 2011. It’s highly sensitive for detecting down’s syndrome. Self pay is now 100-300 USD but a few years ago I think it was as much as 3000. It’s fully covered and encouraged for geriatric pregnancies, which are much more likely to have an extra copy of chromosome 21. The NIPT can screen for the sex of the baby earlier than it can be detected on a scan, so many women elect to have it done. The first trimester ultrasound is around 96% accurate at detection of down’s syndrome.
- Waterluvian 4y ago
  We got this for free in Canada. My first kid had the soft positive marker for it in his first ultrasound (Interesting you say 96% because our doctors said it meant a 1 in 300 chance. Maybe we are talking about different things). So they sent us to Hamilton a week later for genetic screening. The geneticist walked us through the results and said that the tests are effectively negative and now his odds are something like 1 in 5000. This is all to say: indeed they have non-invasive tests and they’re very accessible.
  - jpollock 4y ago
    Without knowing the number of tests performed, you can both be correct. Theirs would be the false positive rate (FPR) or false negative rate (FNR), and yours would be an probability, which takes the FPR (or FNR) rate, the number of tests and the base incidence rate to arrive at 1/300, 1/5000. For example, in Canada, 1/750 of live born babies has Down's [2]. There are about 400,000 births every year in Canada [3]. So, there are 400,000 / 750 = 500 kids with Down's born every year. Assume the test has a FNR rate of 0, and a FPR of 5%. 400,000 * 0.05 + 500 = 20,500 children test positive Odds of positive test indicating Down's (5% FPR): 500/20,500 = 2.4% Not quite the 1/300, but as you said "soft marker", so maybe the FPR is higher for that, vs all the markers? To get to 1/300, the FPR rate on the marker would need to be 37.5%? The 1/5000 is (I believe) a change from a FPR rate to the FNR rate, since the second test is indicating that the disease _isn't_ present. 1/5000 would indicate a negative genetic test will miss one Down's diagnosis in a decade in Canada. Interestingly, it looks like the FRP increases with age, with it being 4% at age 30 (combined ultrasound/blood test)? [1] [1] https://pubmed.ncbi.nlm.nih.gov/11702835/ https://pubmed.ncbi.nlm.nih.gov/11702835/ [2] https://www.canada.ca/en/public-health/services/publications/healthy-living/down-syndrome-surveillance-2005-2013.html https://www.canada.ca/en/public-health/services/publications... [3] https://www.statista.com/statistics/443051/number-of-births-in-canada/ https://www.statista.com/statistics/443051/number-of-births-...

wraithgourd 4y ago

You do realize that before Allied Mastercomputer, her intelligence and yours are basically the same? The only difference is in how good you are to others.

cercatrova 4y ago
By that logic a bacterium and I are also basically intellectually the same before a superintelligence, in the Bostrom sense.
overboard2 4y ago
Why should the values of a superintelligence affect our own?
- vintermann 4y ago
  It shouldn't, unless you derive your idea of worth from your intelligence, which you also shouldn't.
astrange 4y ago
You know that just because you’ve imagined something called a superintelligence doesn’t mean there is such a thing, right?

tomcam 4y ago

sacrosancty 4y ago

Worth noting that some mothers perfer not to test for it because there's an implication they'll decide to kill their baby if it's "defective" which they find horrible and unloving. Eugenics, basically.

GordonS 4y ago

Yes, there is now the NIPT test, which is something like 99% accurate, and involves taking blood from mother and extracting fetal DNA from it. It's more expensive than the older, inaccurate screening test, so here in the UK it isn't routinely offered to parents, or even explained to them. It's offered by private clinics though.