5 ms·

> chances are good that one of the first things you did as a baby was give a DNA sample to the government. This seems pretty disingenuous - yes you gave a bloo

by jjcon 4y ago

> chances are good that one of the first things you did as a baby was give a DNA sample to the government. This seems pretty disingenuous - yes you gave a blood sample (which has DNA in it) but no DNA genome sequencing is taking place - they simply check it for a series of disorders to make sure a baby is healthy and yes gather aggregate data on prevalence of disorders at the population level.

bombcar 4y ago
But do they keep it somewhere for further analysis later (very useful medically if you want to backtest things) or do they programmatically destroy it?
- jjcon 4y ago
  In nearly every western country (EU countries, Canada, Australia, New Zealand etc) the samples are securely stored indefinitely - in the US it depends on the state but many do keep the samples there as well. That does not mean they are readily accessible- there have been cases of misuse but it is extremely rare. From a DNA perspective one can only use the Guthrie test samples for about a decade after collection so yes, in a worst case abuse scenario we have cards that could be mined for DNA across a bunch of <10 year olds.
  - jxf 4y ago
    > From a DNA perspective one can only use the Guthrie test samples for about a decade after collection Why is that? Is it because of sample degradation of some kind?
    - jjcon 4y ago
      Yes - blood must be kept at very specific temperatures and conditions if you want to preserve its usefulness in DNA sequencing - most of these are dried blood cards without strong controls which makes them not particularly useful for good DNA data.
      - User23 4y ago
        Scientists have extracted usable DNA from from 7000 year old corpses. I imagine the technology exists for a decades old blood sample if it’s stored at least somewhat properly.
        jjcon 4y ago
        Yes that is very true - There is however quite a bit of difference between a full corpse that is mildly preserved and a dried fleck of blood - a big difference too between a stored fluid blood sample and these pinprick dried sample.
        xeromal 4y ago
        It's probably prohibitively expensive at the moment.
crackercrews 4y ago
Would you prefer it said "blood sample that can later be mined for DNA"? No one has a problem with the initial health screen. The problem is that they keep it around later in a form that can be used like this.
- jjcon 4y ago
  Maybe - the blood isn’t collected for DNA sequencing so they aren’t DNA samples. Furthermore DNA could only be realistically extracted from them for limited time (about a decade). If you want to view it as a DNA bank, it’s a pretty terrible and temporary one.
  - crackercrews 4y ago
    Would love to see a citation for your second claim.
    - jjcon 4y ago
      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883779/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883779/ “We and others recently have shown that DNA extracted from Guthrie cards (up to a decade old) or blood spots can be used to perform whole-genome methylation analysis”
      - crackercrews 4y ago
        Is a whole geneome methylation analysis needed for criminal prosecution? Seems like the bar would be lower there. You don't need to know the whole sequence in order. You're just comparing it against a sample to see if there are enough matches to establish a linkage. I'm no expert though. Hopefully others can weigh in.
      - sammax 4y ago
        I don’t know why they write that, but one of the papers they quote for that claim reported success with samples up to 19 years old and in turn cites a paper that reported “genotyping whole-genome-amplified DNA” from up to 25 year old blood spots. I don’t know what this means exactly, it definitely isn’t the methylenation thing, but I think it’s a good indication that blood much older than a decade is viable. Both of these papers also report no differences in results between older and younger samples, only between different extraction methods and amounts.
PostOnce 4y ago
They absolutely use these in court (incl. criminal prosecution) in New Zealand and have since at least 2000: https://www.nzherald.co.nz/nz/lawyer-challenges-courts-right-to-access-babies-blood/6NGOO6FHXRPD3VCLBUJSA47CPE/ https://www.nzherald.co.nz/nz/lawyer-challenges-courts-right... and https://www.stuff.co.nz/national/crime/97840280/parents-upset-at-police-access-to-baby-dna https://www.stuff.co.nz/national/crime/97840280/parents-upse... You can fill out a form and demand they return the samples to you. Even if you can trust the government today, there is no guarantee they can be trusted tomorrow. cf. the abortion stuff in America.

by jjcon 4y ago

bombcar 4y ago

But do they keep it somewhere for further analysis later (very useful medically if you want to backtest things) or do they programmatically destroy it?

jjcon 4y ago
In nearly every western country (EU countries, Canada, Australia, New Zealand etc) the samples are securely stored indefinitely - in the US it depends on the state but many do keep the samples there as well. That does not mean they are readily accessible- there have been cases of misuse but it is extremely rare. From a DNA perspective one can only use the Guthrie test samples for about a decade after collection so yes, in a worst case abuse scenario we have cards that could be mined for DNA across a bunch of <10 year olds.
- jxf 4y ago
  > From a DNA perspective one can only use the Guthrie test samples for about a decade after collection Why is that? Is it because of sample degradation of some kind?
  - jjcon 4y ago
    Yes - blood must be kept at very specific temperatures and conditions if you want to preserve its usefulness in DNA sequencing - most of these are dried blood cards without strong controls which makes them not particularly useful for good DNA data.
    - User23 4y ago
      Scientists have extracted usable DNA from from 7000 year old corpses. I imagine the technology exists for a decades old blood sample if it’s stored at least somewhat properly.
      - jjcon 4y ago
        Yes that is very true - There is however quite a bit of difference between a full corpse that is mildly preserved and a dried fleck of blood - a big difference too between a stored fluid blood sample and these pinprick dried sample.
      - xeromal 4y ago
        It's probably prohibitively expensive at the moment.

crackercrews 4y ago

Would you prefer it said "blood sample that can later be mined for DNA"? No one has a problem with the initial health screen. The problem is that they keep it around later in a form that can be used like this.

jjcon 4y ago
Maybe - the blood isn’t collected for DNA sequencing so they aren’t DNA samples. Furthermore DNA could only be realistically extracted from them for limited time (about a decade). If you want to view it as a DNA bank, it’s a pretty terrible and temporary one.
- crackercrews 4y ago
  Would love to see a citation for your second claim.
  - jjcon 4y ago
    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883779/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3883779/ “We and others recently have shown that DNA extracted from Guthrie cards (up to a decade old) or blood spots can be used to perform whole-genome methylation analysis”
    - crackercrews 4y ago
      Is a whole geneome methylation analysis needed for criminal prosecution? Seems like the bar would be lower there. You don't need to know the whole sequence in order. You're just comparing it against a sample to see if there are enough matches to establish a linkage. I'm no expert though. Hopefully others can weigh in.
    - sammax 4y ago
      I don’t know why they write that, but one of the papers they quote for that claim reported success with samples up to 19 years old and in turn cites a paper that reported “genotyping whole-genome-amplified DNA” from up to 25 year old blood spots. I don’t know what this means exactly, it definitely isn’t the methylenation thing, but I think it’s a good indication that blood much older than a decade is viable. Both of these papers also report no differences in results between older and younger samples, only between different extraction methods and amounts.

PostOnce 4y ago

They absolutely use these in court (incl. criminal prosecution) in New Zealand and have since at least 2000: https://www.nzherald.co.nz/nz/lawyer-challenges-courts-right-to-access-babies-blood/6NGOO6FHXRPD3VCLBUJSA47CPE/ https://www.nzherald.co.nz/nz/lawyer-challenges-courts-right... and https://www.stuff.co.nz/national/crime/97840280/parents-upset-at-police-access-to-baby-dna https://www.stuff.co.nz/national/crime/97840280/parents-upse... You can fill out a form and demand they return the samples to you. Even if you can trust the government today, there is no guarantee they can be trusted tomorrow. cf. the abortion stuff in America.