4 ms·

Back when I used to do pedigree analysis, the general rule of thumb was 1/10 chance that the father wasn't what was stated in the pedigree. You would run the

Back when I used to do pedigree analysis, the general rule of thumb was 1/10 chance that the father wasn't what was stated in the pedigree. You would run the analysis and get absolute nonsense results, and then you'd swap a father for an uncle, or a mother for her daughter, and the alleles would all just suddenly line up. We would never tell the families, and since the pedigrees were anonymized before being published there was no need to. Some secrets are just best kept buried.

BiteCode_dev 2y ago
Same with blood types. Clearly lots of people never listen in biology class.
- pandemic_region 2y ago
  As one of the referred 'lots', care to explain a bit more?
  - BiteCode_dev 2y ago
    Some combinations are impossible. E.G: both biological parents cannot be A and the kids be AB
jorvi 2y ago
What is nuts is that in some countries, its illegal for the father to unilaterally have a paternity test done. I know for France that if you have it done unilaterally and thus illegally you are still on the hook for child support until a legal test is done, which either the mother needs to agree to or needs to be agreed on by the court. IMO a paternity test should just be mandated to be done immediately at birth (or earlier even?). It avoids the tinge of distrust of "oh wow, how could you even think that of me?!" from the mother, whilst giving certainty to the man.
- gmane 2y ago
  I disagree here. Blood tests done at birth are done specifically for the benefit of the child (and with minimal risk to the child). A paternity test has no benefit for the child (it doesn't tell you who the father is, simply who the father isn't) and a ~1% risk of harm to the child. The period immediately after birth is one of the most dangerous times for children, and we (should) specifically take action to protect them in a moment where they are at risk and have no agency. A paternity test would increase the risk of harm to the child (either through violence, deprivation, or neglect). We didn't even get to the subject of possible violence against the mother either, which is likely.
  - jurenbert 2y ago
    [dead]
  - gggtttkkk88 2y ago
    [flagged]
    - cindyllm 2y ago
      [dead]
    - gmane 2y ago
      The internet is truly a wild place. You can say something like "We shouldn't do mandatory paternity tests at birth because they bring no benefit to the child" and someone responds with "So you're saying we shouldn't stop wife beaters?" No bitch, that's a whole different sentence. What the fuck are you talking about.
      - gggtttkkk88 2y ago
        No chance, bucko. The essence of your comment is that paternity testing should be avoided because there is no benefit to children and there is potential harm to women. Your focus was not on the mandatory nature of any such testing. And I believe you understand my analogy in spite of your faux confusion and outrage.
ttyprintk 2y ago
Thanks, that answers my questions about how pedigrees were preprocessed for a study like this: 1. Isn’t there a very high chance any particular male’s result is true for both father and uncle? 2. For young teen mothers, sometimes a family of older mother and two assumed siblings is really grandmother, mother, child. Paternity and slightly maternity are secretly, generationally obscured. So two assumed female siblings might share less than half-sibling measures of autosomal DNA.
- tetris11 2y ago
  It's been a while and I was always a bit shaky on the actual genetics, so hopefully an actual expert can weigh in here, but as far as I remember - For 1 it depends on the penetrance model (a score on whether all individuals with the disease allele(s) express the disease phenotype: 1=all, 0.5=some, etc.) along with whether the allele's mode of inheritance is recessive/dominant, X-linked or not, and how consanguineous/inbred the pedigree is. If I remember it right, if a father/son combo always express the disease allele, then the pedigree is x-linked recessive. If you see an uncle/son combo, and test for it, and the linkage score for the region of interest (the likelihood that the disease travels with the ROI computed over all individuals) goes up, then it's pretty suspect. For 2, you could see the distribution of alleles without much computation. Siblings are expected to share X%, relatives Y%, unrelated Z%. By fitting to these bands, you could already see if the distribution of alleles was suspect. We never tested for mtDNA though, I don't think there were many chipsets for it back then.
  - ttyprintk 2y ago
    Awesome, I appreciate that. Ok so my question for the researcher would be: 1. Circumstances where both mtDNA and Y chromosome are shared between biological father and pedigreed father. I think the Biblical term is Levirate marriage. 2. Circumstances without Y where maternity is secretly disputable and paternity uncontentious. I think the researcher called this secret adoption. At distances longer than several generations, is there noise in the measure of autosomal matches such that you cannot detect these?
    - 2y ago
mcphage 2y ago
What is pedigree analysis? Are you talking about dogs, or people?
- tetris11 2y ago
  linkage, haplotype, and variant analysis

BiteCode_dev 2y ago

Same with blood types. Clearly lots of people never listen in biology class.

pandemic_region 2y ago
As one of the referred 'lots', care to explain a bit more?
- BiteCode_dev 2y ago
  Some combinations are impossible. E.G: both biological parents cannot be A and the kids be AB

jorvi 2y ago

What is nuts is that in some countries, its illegal for the father to unilaterally have a paternity test done. I know for France that if you have it done unilaterally and thus illegally you are still on the hook for child support until a legal test is done, which either the mother needs to agree to or needs to be agreed on by the court. IMO a paternity test should just be mandated to be done immediately at birth (or earlier even?). It avoids the tinge of distrust of "oh wow, how could you even think that of me?!" from the mother, whilst giving certainty to the man.

gmane 2y ago
I disagree here. Blood tests done at birth are done specifically for the benefit of the child (and with minimal risk to the child). A paternity test has no benefit for the child (it doesn't tell you who the father is, simply who the father isn't) and a ~1% risk of harm to the child. The period immediately after birth is one of the most dangerous times for children, and we (should) specifically take action to protect them in a moment where they are at risk and have no agency. A paternity test would increase the risk of harm to the child (either through violence, deprivation, or neglect). We didn't even get to the subject of possible violence against the mother either, which is likely.
- jurenbert 2y ago
  [dead]
- gggtttkkk88 2y ago
  [flagged]
  - cindyllm 2y ago
    [dead]
  - gmane 2y ago
    The internet is truly a wild place. You can say something like "We shouldn't do mandatory paternity tests at birth because they bring no benefit to the child" and someone responds with "So you're saying we shouldn't stop wife beaters?" No bitch, that's a whole different sentence. What the fuck are you talking about.
    - gggtttkkk88 2y ago
      No chance, bucko. The essence of your comment is that paternity testing should be avoided because there is no benefit to children and there is potential harm to women. Your focus was not on the mandatory nature of any such testing. And I believe you understand my analogy in spite of your faux confusion and outrage.

ttyprintk 2y ago

Thanks, that answers my questions about how pedigrees were preprocessed for a study like this: 1. Isn’t there a very high chance any particular male’s result is true for both father and uncle? 2. For young teen mothers, sometimes a family of older mother and two assumed siblings is really grandmother, mother, child. Paternity and slightly maternity are secretly, generationally obscured. So two assumed female siblings might share less than half-sibling measures of autosomal DNA.

tetris11 2y ago
It's been a while and I was always a bit shaky on the actual genetics, so hopefully an actual expert can weigh in here, but as far as I remember - For 1 it depends on the penetrance model (a score on whether all individuals with the disease allele(s) express the disease phenotype: 1=all, 0.5=some, etc.) along with whether the allele's mode of inheritance is recessive/dominant, X-linked or not, and how consanguineous/inbred the pedigree is. If I remember it right, if a father/son combo always express the disease allele, then the pedigree is x-linked recessive. If you see an uncle/son combo, and test for it, and the linkage score for the region of interest (the likelihood that the disease travels with the ROI computed over all individuals) goes up, then it's pretty suspect. For 2, you could see the distribution of alleles without much computation. Siblings are expected to share X%, relatives Y%, unrelated Z%. By fitting to these bands, you could already see if the distribution of alleles was suspect. We never tested for mtDNA though, I don't think there were many chipsets for it back then.
- ttyprintk 2y ago
  Awesome, I appreciate that. Ok so my question for the researcher would be: 1. Circumstances where both mtDNA and Y chromosome are shared between biological father and pedigreed father. I think the Biblical term is Levirate marriage. 2. Circumstances without Y where maternity is secretly disputable and paternity uncontentious. I think the researcher called this secret adoption. At distances longer than several generations, is there noise in the measure of autosomal matches such that you cannot detect these?
  - 2y ago

mcphage 2y ago

What is pedigree analysis? Are you talking about dogs, or people?

tetris11 2y ago
linkage, haplotype, and variant analysis