Midwives have been told about the benefits of “close relative marriage” in training documents that minimise the risks to couples’ children.

The documents claim “85 to 90 per cent of cousin couples do not have affected children” and warn staff that “close relative marriage is often stigmatised in England”, adding claims that “the associated genetic risks have been exaggerated”.

  • nyankas@lemmy.world
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    14 days ago

    I wonder where this 15% figure comes from. All the research I can find estimates the probability for these disorders at around 2-4% for first degree cousins. This is about the same as becoming a mother at 40 with a non-related man.

    The article only talks about some NHS training documents and is very opinionated in style. Smells like a snappy headline about a controversial topic was more important than proper research.

    • qualia@lemmy.world
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      14 days ago

      Plus in the absence of any power dynamic* why shouldn’t absolutely anyone be allowed to choose to be in a relationship with literally anyone else? Especially as people are increasingly choosing to not reproduce.

      • If this is even possible
  • Chozo@fedia.io
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    14 days ago

    Am I the only one that thinks 15% is way too high of a chance to be rolling the dice like that? I’ve played enough XCOM to know that even a 99% success rate will still bite you in the ass.

      • ryven@lemmy.dbzer0.com
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        14 days ago

        It lies in your favor, though. On difficulties below the highest, the modern games have hidden modifiers that affect the hit chance that you can’t see, but all of them are cheating for you. IIRC your hit chance secretly increases when you have missed shots recently, when you have dead soldiers, when you are outnumbered, and maybe some other things.

  • Railcar8095@lemmy.world
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    14 days ago

    Devils advocate: I have a genetic defect that has 50% chance of being passed to my children. It causes bone tumors that range from stetic to life changing.

    We only managed to ensure it wasn’t with expensive DNA tests pre - implantation.

    Should I be barred from marriage if I can’t pay for that?

    It’s not a hypothetical

    • boonhet@sopuli.xyz
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      14 days ago

      Not sure what marriage has to do with it in either case tbh. The cousinfuckers can have babies without getting married and so can you lol

      But I do understand your point. It’s an ethical dilemma and not a simple one. I mean on a policy level. I imagine on a personal level it’s easier to say “the risk is too great, I won’t do it” as opposed to policymakers saying “the risk is too great, you shouldn’t be allowed to have children”

  • UncleArthur@lemmy.world
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    15 days ago

    Excuse me! Loads of Western European countries allow full incest (e.g. Belgium, France, Spain, etc.) so let’s not pick on us Brits for allowing cousins to fuck.

    • Eager Eagle@lemmy.world
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      14 days ago

      not making illegal and support from the national health service are vastly different things. 15% is a disastrous rate for public health.

      • workerONE@lemmy.world
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        14 days ago

        But it’s not a 15% risk. Unrelated couples have a 3% chance of having a child with a birth defect while cousins have a 5% chance of having a child with a birth defect.

        • stephen01king@piefed.zip
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          14 days ago

          Isn’t the problem being that the probability increases with each subsequent generations? That’s why having a child with a cousin should be discouraged, to prevent the accumulation of bad recessive genes.

          • workerONE@lemmy.world
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            14 days ago

            If you have one person with recessive genes and one person with dominant genes, then the baby will have the dominant gene. So if the grandparents were cousins both with recessive genes it wouldn’t matter, as far as I know.

            • stephen01king@piefed.zip
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              14 days ago

              The thing is, with subsequent incestual generations, the likelihood of the recessive gene manifesting increases a lot. So, the problem is not a single generation of incest, it’s the normalisation of incest that might lead to multiple generations doing it.

              • workerONE@lemmy.world
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                14 days ago

                Oh I see what you’re saying. I did some reading earlier that said that in a lot of places 20% - 40% of all marriages are to first cousins.

            • Tollana1234567@lemmy.today
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              14 days ago

              theres also dominant alleles that are the disease state, it also gets complicated when theres partial penetrance since its only half an half.

      • UncleArthur@lemmy.world
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        14 days ago

        Pretty sure they are. Incestuous relationships between consenting adults (with the age varying by location) are permitted, including in the Netherlands, France, Slovenia, and Spain. Why not check before making such a statement?

        • Railcar8095@lemmy.world
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          14 days ago

          Not only wrong, but also childish about it. First, this topic is about marriage. They are not taking about letting them be in a relationship, but marriage.

          And marriage between siblings is not allowed in several countries you mentioned, which you would know if you checked instead of being “pretty sure”.

          Not go be a wrong ass somewhere else.

  • phutatorius@lemmy.zip
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    14 days ago

    You need to parse the sentence a bit. “85 to 90% of cousin couples do not have affected children” does not mean that the odds of one child being born with a hereditary genetic defect is 15%. It means that, for the average family size of a first-cousin couple, the odds are 10-15% that at least one of the kids is affected.

    So, let’s conservatively say the average family size among those who marry first cousins is 3. The odds of at least one in those three kids having a genetic defect are stated to be 15%. So that means the odds of any individual kid whose parents are first cousins having a genetic defect are a bit under 5% (the odds of a given event happening at least once in three independent trials).

    The odds will be substantially lower if that 15% figure were based on a larger family size than 3.

    As a baseline, tn the UK, the odds in the overall UK population of a genetic defect occurring are around 2.55%.

    So the risk is roughly double the baseline for any individual child. But the way the numbers are presented makes it seem misleadingly high and has led to predictable screeching from the usual quarters. There is also no measure of severity. For example, despite my parents being unrelated, I have a genetic defect that causes high cholesterol levels in my blood. However, it’s cheaply treatable (woo hoo, statins!) so its impact on pubilc health is next to nil.

    I’d favour banning marriages where the partners have first-cousin and closer degrees of consanguinity, but I also see the point of not catastrophising the actual impact.

  • bus_factor@lemmy.world
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    15 days ago

    Lots of things lead to increased risk of birth defects, like having children after the age of 30. I thought it was pretty well known that the risks associated with inbreeding drops off pretty sharply at the cousin level? At that point I think the appropriate reaction is social stigma, but not legal ramifications.

    • nfh@lemmy.world
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      14 days ago

      It also compounds over generations; if you’re the child of first cousins, you really should seek someone who it would take genealogy research to find a common ancestor with. If you’re not, it’s still a serious risk to have kids with anyone too closely related, but level ramifications seem really harsh, especially thinking of situations like adoption where someone could end up there accidentally. And to your point, it isn’t the only way to end up with that kind of risk profile.

      • phutatorius@lemmy.zip
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        14 days ago

        Good thing that it’s possible for a couple to take a test that gives a good measure of their degree of consanguinity.

        This is a particular risk not only in countries with first-cousin marriage, but in those with small founder populations. For example, Iceland, where the government provides this measure to any couple who asks, so that they can make an informed decision about the risk before reproducing.

        And ethno-nationalists can choke on this fact: the best strategy to reduce the risk of genetic defects is out-marriage. The less closely genetically similar two partners are, the lower the odds of autosomal recessive disorders afflicting their offspring. So I did the rational thing, and married someone whose ancestors came from a different part of the world than mine.

    • TheGrandNagus@lemmy.world
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      14 days ago

      It’s a big thing in the Pakistani and British-Pakistani communities. The biggest spot in all of Europe for incest is in Bradford, after all.

      I highly doubt those demographics vote Reform. Reform voters hate these people.