When I saw this referenced in an online discussion I thought it had to be some racist hate nonsense, but apparently it’s a very real and serious thing re multiple cousin marriages across generations and birth defects.
Consanguinity and reproductive health among Arabs
Is this enough of a problem that some countries should changes laws about the legality of 1st cousin marriages?
I started a thread on this a while back:
http://boards.straightdope.com/sdmb/showthread.php?t=793332
Iceland has a similar problem with lack of genetic diversity and I believe they use genetic testing, among other things to make sure closely related people don’t have kids. I don’t know how easy it would be to change those cultural norms, but maybe a few generations from now at least the ones that are immigrants in Western countries will probably branch out and have children with people who aren’t their cousins.
From memory, the statement in Pool’s post above
was related to cases where first cousin marriages go back two or more generations; something that seems to be more common among this group.
First cousin marriage is legal and not thought exceptional in the UK. The problems seem to arise when the children of first cousins marry each other. I believe that there have been some efforts to convince the British Pakistani population that this is not a good idea.
A lot of cultures have examples of cousin marriage.The royal families of Europe are an example and they consequently suffered from some debilitating genetic disorders. This is evident in the current British Royal family, where the Queen is a second and third cousin to Prince Phillip. Inbreeding among hereditary monarchs is a tradition that goes back to the pharaohs of Egypt.
Cousin marriage is also practiced in some influential families such as the Rothschilds.I guess the intention was the same: to preserve political and financial power within an extended family. In the UK there is a tradition of cousin marriage in some sections of the Pakistani community and this leads to some serious health issues.This may well be as a result of migrant families trying to preserve influence and assets in both the old and the new country.
How far religion plays a part in this is an interesting question since there seem to be examples of cousin marriage tolerated in both Christianity, Judaism and Islam. I would hazard a guess that it is more to do with preserving family wealth and power in political structures that are based on close relationships within extended family groups.In many countries cousin marriage is legal, it believe it is in the UK. It does not always result in some nasty illness. I guess it depends on what recessive genes are lurking in the family genome. The Pakistani community in Bradford has been the subject of a lot of research and there are community health programmes to address this issue.
Interestingly, in Iceland, which also has a restricted genepool and lots of useful family records, which makes it a hotspot for genetic research; there is a smartphone app that can make people aware of their lineage in order to avoid cousin relationships. Whether that works on beery Saturday night in Reykjavik, that is another matter.
I recall a discussion of this in some article. It apparently defines “clans”. People look out for and protect fellow extended clan/family members with whom they have a deeper blood connection. First-cousin marriages might be part of it, but it also includes a lot of second and tird cousin marriages, people who share the same “family group”. Like the royal families of Europe, one could trace convoluted connections to another through several ancestors on both sides of their family. Of course, when the rich and influential also have multiple wives and dozens of children, that adds the convolution.
This was a protective thing -in a turbulent region, you needed someone to rely on, and blood relatives were the most reliable (supposedly) compared to idealists and strangers. Many cultures place emphasis on extended family connections.
(As an example, consider the caste system in India preventing excessive intermixing between parallel geographic groups - a person’s marriage choices in a particular area would be more limited to a smaller group, many of whom may share ancestors.)
There was even a suggestion that some middle east disputes, such as Hamas and the PA, were as much or more about clans and their vendettas than politics.
Birth defects are typically about recessive genes. A person has a defective gene because someone, somewhere in their ancestry, had a mutation in the replication of their genes. (There’s a suggestion that many cases of miscarriage are due to problems with defective genes- nature’s way of culling the errors) Most defectives don’t matter, because everyone gets two (except XY) so typically the complete one will be dominant and compensate. However, if you tend to pair up with others who share several recent common ancestors rather than someone from a different area of the country who has no family connection - the statistical odds that one of these defective genes will pair up is pretty high. It’s not so much they marry cousins, as they marry closely connected family.
Not sure if the problem is also that when a small group migrate to a new country and expect to carry on the intra-clan marriage lifestyle, the pool of potential mates gets even smaller and the risk greater.
(Then there’s the issue mentioned in one of Malcolm Gladwell’s books - that Michigan, with its high Muslim population, experienced a higher rate of neonatal issues in certain times of the year - specifically, when children conceived just before Ramadan were born. Fasting during Ramadan is not necessary for women who are pregnant, but fasting for up to 16 hours in a summer month for women who don’t necessarily realize yet they are pregnant is not good for the baby.)