Laws banning marriage between first cousins are based on outdated assumptions about a high degree of genetic risk for offspring and should be repealed, according to a population genetics expert.
In an opinion article published in the US open-access journal PLoS Biology, Professors Hamish Spencer and Diane Paul argue that laws against cousin marriage are ill-advised. “Neither the scientific nor social assumptions behind such legislation stand up to close scrutiny,” says Professor Spencer. For example, a 2002 expert review of studies regarding birth defects in offspring of cousins found that the risk was much smaller than generally assumed.
The US National Society of Genetic Counselors (NSGC) report estimated the average risk as 1.7 – 2 per cent higher than the background population risk of congenital defects and 4.4 per cent higher than general risk for dying in childhood.
“Women over the age of 40 have a similar risk of having children with birth defects and no one is suggesting they should be prevented from reproducing. People with Huntington’s Disease or other autosomal dominant disorders have a 50 per cent risk of transmitting the underlying genes to offspring and they are not barred either,” Professor Spencer says.
I’ll keep my mouth shut on this one. I have kin who read my blog posts.
I can understand this within one generation. The real question is what happens, what are the statistics, when this happens over several generations? Seems to me that’s where the real risk lies.
I was going to comment, but a picture…
… in a report published by doctors Frank Bundchen, George Alba, and Alexander Biel…
… The report has not been widely accepted in the scientific community largely due to a passage in the report’s conclusion encouraging all supermodels and leading actresses to consider whether that nerdy cousin who has become a successful gene researcher might not be so bad looking after all.
We get states like West Virginia.
I think they have a point if they couple is otherwise not related.
However in Ancient Rome at least for some time they required you be at least 7 levels out.
The reason why is the elite could only marry their own elite and this had been going on for hundreds of years with a relatively small percent of the population being elite. They must have been extremely inbreed.
In my own community this meant that you had things like two of the White boys married sisters.
Two of their daughters married men who were first cousans and third cousins.
Most of the people in the community could trace relationships to others on both sides of their families though it might go back a few generations.
In other words when you are related in several different ways there is apt to be a build up of dangerous same genes. This sort of thing has been very common historically because people were limited to spouces within easy travel distance of them.
With current levels of mobility this sort of thing is now much less common. Most people are marrying people from much more remote locations.
To the best of my knowledge nobody in my extended family in my generation or later married anybody with whom they could reasonibly be considered to be related nor are there any double cousins. Oops the Hagan twins married a father and son!
I don’t know about this but my uncle and his second cousin married accidentally or so they say, and their kids are not right in a major way, no not one of the 4 of them.
My great-great(-great ?)grand uncle married his brother. Of course this was shortly after he became an ordained priest. It was a big deal back in the 1870s.
#6, Bubb,
I understand. My mother in law is a Republican too. We think it might be congenital.
I got a cousin that has one better than normal and three that mainly just didn’t mentally mature. Part genetic and part mama.
However neither he nor his wife were related in any way shape form or fashion.
There is always a risk with children. I suspect most families have the genes to produce a gifted person and one who is if far from gifted.
I have to agree to not allow this. Even my people whom are near bushmen doesn’t allow this for the same reason. In fact, you can’t marry anyone with the same last name as you or another clan of a different last name that is banned. The latter is true for each last name, meaning each last name cannot married a specific last name because they are too closely related.
So if bushmen people know and is against this, why is a advance culture like US even debating about it? The problem is you never know what will happen but do you really want to take the chance? There’s too much history on this, even if few, to be doing it. Take your risk if you do consider it though.
#5
I think part of the problem with most in the US is their inability to trace all their relationships. For our people, Hmong, family and relationship is very important. When you meet someone or a family eventually and quickly you will find out how closely related you are. This is all done by memory mind you, pass from generation to generation. I’m always surprise when I meet and find out how close people are to me and my family.
Supe! Kara’s only 15!! Knock it off!
No Arrested Development reference yet? Really?
Remember, 16 will get you 20!
And of course this has no bearing on the fact that most of the human race was begun with inbreeding within small isolated villages that eventually became cities.
That the entire human race is based upon the dea of not only first and second cousins having offspring, but sex with aunts, uncles, mothers, fathers, brothers and sisters.
Face it the gene pool is already tainted. You cannot untwist the cord, the damage is done.
The only thing we can do is not twist it further.
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Not to be promoted nor prohibited. Love is sacred above all things.
Where are all the people protesting this human rights violation?
The very basics of Mendelian genetics neither accepts nor rejects the notion that breeding between first cousins significantly elevates the risk of a detrimental outcome. In fact, you could argue the reverse: preventing this breeding increases the chance of losing a genetic trait that is uniquely beneficial, say a natural resistance to a particular disease. All in all, the issue is not as much a scientific one as it is the result of the propagation of social/cultural beliefs – often based on anecdotal observation of a perceived association between an outbreak of disease and inbreeding in early history of a culture.
Often, a few would use inbreeding in certain southern states, assuming that this is even a significant differentiator, as the cause of any ill-state of the people. Personally, I believe socio-economical effects play a larger role than genetics.
All that said, after a lifetimes of taboo associated with breeding between cousins, no amount of scientific evidence (or the lack thereof) is going to change how people feel about the matter.
#20–DhanuShan==nice direct statement of the issue, but I think you are wrong. I’m thinking that statistically close interbreeding does “highlight” the action of “characteristics of concern.” If that characteristic is hemophilia, thats bad, hence the reputation. If the characteristic is good, say creation of Vitagmin D from sunlight, it is good and not chalked up to “inbreeding.” So is this a “neutral” situation? I’d say “no.” When the whole popultion is not spreading all the genes around, you are more likely to not get hemophilia and more likely not to get increased Vitamin D. Taking account of both scenario’s, only the close breeding increases the odds of bad outcomes.
To that end–how about those incestuous kiddies of Adam and Eve and later Noah’s kiddies?
We are all inbred multiple times over, and the bad genes did predominate.
#21
I agree that the damage is done.
I just figure that we found out, metaphorically, that hurling rocks at our glass house made holes in the glass, why keep hurling stones when its obviously counterproductive?
No more inbreeding thanks, we’ve had more than enough.
“A million years of evolution, we get Danny Qayle!” – Danny Elfman
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Speaking of inbreeding, genetics, gene manipulation, I bring you the end of the world:
http://news.yahoo.com/s/ap/20081225/ap_on_sc/do_it_yourself_dna
ie==gene splicing as a hobby.
Better start working on your bucket list asap.
Thank you for you sharing information
There’s a family line in Louisiana that inbreeds so much all the men have tunnel vision and severe myopia. God knows what the women have, probably 3 vaginas.