First cousin marriage

[Danceswithwhippets]

I don’t think I know (family or wider) anyone in a first cousin marriage.
I listened to this interesting podcast.
There is quite an ick factor about it -the podcaster (a “data journalist” -I didn’t know there was such a thing but I think we need them!) refers to it as a taboo. I suppose that maybe correct, if you do regard it as a part of the incest taboo.
She suggests the ick factor may be a reflection of racism, as first cousin marriage is now unusual in western societies.
What I find interesting is that although in western societies it’s largely frowned upon, few western countries legally prohibit it or restrict it.
Listen to what she says is the genetic evidence about risk -she seems to consider, for first cousin marriages, a doubling of risk of a major genetic problem from 3 to 4% (ie to 6 to 8%) is not great. I wouldn’t agree with that.
Any geneticists, or for that matter any first cousin marriages out there?

It's on BBC Sounds
www.bbc.co.uk/sounds/play/p0ch1vn3#xtor=CS8-1000-%5BPromo_Box%5D-%5BNews_Promo%5D-%5BNews_Promo%5D-%5BPS_SOUNDS~N~p0ch1vn3~P_AmINormalCousinMarriage_SEG_PNC%5D

You wouldn't buy a puppy with a high breeding coefficient so it seems careless to shag a cousin!

That's interesting. Is the difference significant and does it change after 36.

I wish I'd known that when a doctor was shouting at me for declining tests when I was pushing 40, he was incensed as "there won't be much time to sort out the amnio and abortion if necessary" if I left it much longer.

Although thinking about it for me it was baby 4, I wonder if that makes it riskier or not?

It is very complicated but fascinating if you start thinking about it.

@DandyMandy i think one person mentioned Ireland? But plenty more have mentioned Birmingham and Bradford?

For whoever mentioned autism - it’s not about guessing there is a hereditary component to certain disabilities or conditions. It’s about knowing about genetics. We know cystic fibrosis is genetically carried. We know haemophilia is. So yes, there should absolutely be programmes for communities more adversely affected so they can make educated decisions instead of just perpetuating terrible illnesses.

Where I live I quite often see families with several severely disabled children. It must be really hard.

I wasn't blaming Irish for marring Irish - if that's to my posts - that's a huge leap.

In fact most of the population I was talking about identify as English - having been born for generations in England but originated with small population from Ireland and stuck to same location in England.

Example I was talking about people - a white population weren't aware they were related often just knew their family had been in area for several generation and when traced back found Irish link- and they weren't marring their cousins - but it was an example of a community closely related having more rare genetic problems.

I'm now wonder if the basic DNA explanation was in response to my pointing out Queen Victorian - and idea the haemophilia mutation was de novo - something more common with older parents and thus wasn't a good example of inbreeding.

investigativegenetics.biomedcentral.com/articles/10.1186/2041-2223-2-14

The origin of the royal haemophilia mutation is unknown: it most likely appeared de novo in Queen Victoria, although the absence of the disease in her forebears has contributed to the alternative hypothesis that she might have been illegitimate [6]. The mutation may now be extinct, and for concerned living matrilineal descendants in Spain, this could be confirmed by a specific DNA-based test now that its molecular nature is known. The mutation's existence within the British royal family was no signal of inbreeding; in fact, consanguineous marriages among the royals over recent generations have been rare,

Ireland has the highest incidence of CF in the world- 3 times that of the U.K. and Ireland. There is a significantly larger number of patients clustered around the south-west of the country.

We also have a similarly high incidence of celiac disease.

It’s not anti-Irish to wonder why an island whose population was dramatically reduced thanks to a “famine” and huge amounts of emigration now see an increase in some conditions. There was a smaller pool of potential partners to choose from, it gave these genetic issues a perfect foothold.

This pretty much!

There's a very simple answer.
Abortion only became legal in Ireland on 1 January 2019.

@MrsHadley first cousin (or any cousin marriage) isn't considered incestuous in any jurisdiction in the UK.

Screening for genetic conditions that are common in certain ethnicities only comes about when it starts costing the health service more to treat children and shock horror - adults with the condition. (Even then they are pretty shit in doing it.)

Jewish people realising that the NHS wasn't going to screen for diseases that are genetically common in their ethnicity (and yes being Jewish is an ethnicity as well as a religion) started doing their own screening before the NHS in England decided they would pay for it. As much as I can remember - as I was a early teen - at the time the Chief Medical Officer in England had to be shamed into providing screening for Jewish people and other ethnic minorities on the NHS.

@ChiefWiggumsBoy forgot to add the problem with some parents is that the genetic conditions they carry are rare e.g. only specific to that individual family and perhaps a handful of others. So you can't screen for those other than to do the standard tests you do for every woman who is pregnant.

@ancientgran you can have a blood test from about 10 weeks now. I had one at my booking appointment on the NHS.

Maybe they hope they'll have children as intelligent as the Irish 😎

😂😂

More nonsense!

It’s grim. Millions of people on earth and they pick to get with a relation.

Yes that was the test I declined.

I am familiar with the law on abortion- I voted in the referendum myself.

But no that isn’t the entire reason, and I think you know that. There’s no pre-natal screening for celiac disease for example, and CF can only be diagnosed during pregnancy after an amnio, which are done when they know the parents are carriers.

Theres no shame in saying we’re a island people with a small population. I haven’t seen any anti-Irish posts here, and trying to accuse other posters who have commented in good faith is just derailing an interesting thread.

They were second cousins once removed. The Queen was third cousins to her children.

I have worked in Bradford as a health visitor
Co sanguinuity is the official description of this
Its a fact recognised by Public Health in Bradford that first cousin marriages lead to an increased risk of LD in babies and children. Health professionals are given training regards this issue
It is thought to be due to cultural considerations; family resources remaining within the family
Along with a religious element that Gods will is involved and what will be will be

One of the reasons for cousin marriage (not necessarily first cousin) is social: it is thought that the spouses are more likely to get on if they come from a similar family background. Also, in cultures where the marriage is going to be arranged rather than spontaneous, or where there is little chance for people from different sexes to meet socially, the bride and groom are more likely to have met each other and know that they get on. This works, to an extent, if there is a massive pool of cousins to choose from. It fails (in part because of British immigration law) and causes huge genetic problems when there is a small population in this country and a high expectation of people marrying into the same community and family over generations.

No but it's inbred and gross.

So many people on this earth and people choose to shag their cousins.

if you have a dominant (G) and recessive gene (g)
there are 4 possible combinations
GG Gg gG and gg
only a double recessive ie gg gives you the disease Gg or gG means you are a carrier and GG means you neither have it or carry it
so when two parents both Gg or gG have children
there is a 25 % chance of GG unaffected and not a carrier 50% chance of unaffected but carrier status Gg and gG and 25 % of being affected and a carrier gg

if "g" is relatively rare in the population ie 1 in a 100 the chances of two carriers marrying is fairly low say 1 in a 10,000 and their chance of having an affected child is 1 in 40,000

but if someone is a carrier approx 50% of their children will be carriers and 25 % of their grandchildren so if two grandchildren (ie cousins) have children the chances of them both being carriers are not 1 in 100 but 1 in 16 and the chances that their children will be carriers is 1 in 32 and the chance of a child being affected are 1 in 64