Saturday, August 18, 2012

Consanguineous Childbearing and Genes

Some bigots try to justify their prejudice against consanguineous sex and marriage by saying that such relationships inevitably lead to genetic problems. This argument can be refuted on several fronts.

1. Some consanguineous relationships involve only people of the same gender.

2. Not all mixed-gender relationships birth biological children.

3. Most births to consanguineous parents do not produce children with significant genetic problems.

Secondly: there is no statistically significant difference in abortion or stillbirth, in the sample resulting from consanguineous marriages, compared to the sample resulting from marriages between non-relatives.

Thirdly: There is a statistical difference between the age of the mother, in the sample resulting from consanguineous marriages and the one resulting from exogamous marriages, and this difference is considered by many scientists as the causative in chromosomal defects.

Fourthly: The researcher analyzed these results by several statistical methods, assuming that consanguineous marriage has an effect in chromosomal defect, but the results repudiated this assumption.

Something else to keep in mind…

But if consanguineous marriage was prohibited in the society or rare, then this prohibition will lead to the survival of many individuals carrying the disease-causing genes. Therefore, the chance for possible intermarriage of two non-relatives carrying the disease-causing genes for a particular disease will be considerable; hence, the emergence of this disease in these communities. The best example of this disease is Cystic Fibrosis of the Pancreas. This disease is governed by a recessive gene, common in Britain, despite the scarcity of consanguineous marriages. This is due to the presence of a high proportion of carriers of the disease-causing gene, as explained previously, which leads to increased chance of intermarriage between the carriers of this disease, and therefore its manifestation among their progeny.
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  1. The consanguineous relationships in the article you linked to were all 1st cousins, or further removed. Also the site you linked to was created by a Muslim sect in which cousin marriage is considered preferable.

    The risk of birth defects when siblings have kids together, or parents have children with their own kids, is well known.

    I do agree that laws prohibiting consensual sex between related adults are invalid, but only because contraceptives allow us to avoid conception. If there were no way to avoid becoming pregnant, then the laws against incest would be completely appropriate.

  2. Thank you, Anon.

    Yes, in many places first cousins are denied the freedom to marry, and social stigmas are hurled at them as well, so including them in this is important.

    The purpose of this blog is to argue for full marriage equality and the rights to love and sex as well, not necessarily reproductive rights, so I won't spend a lot of time right now going off on that tangent other than to point out that birth defects are also more common to children born of older mothers, but there's no stigma assigned to that. These days, older women having children is actually especially celebrated, at lease in the US. There is certainly no law against it. But the "mutant babies" argument is often hid behind by those prejudiced against certain relationships.

  3. Reproductive rights are no less important. They should be forcefully defended.

    Genetic counselors have DNA analysis methods available (e.g., Counsyl) and fertility specialists have them as well (PGD - Preimplantation Genetic Diagnosis).

    The technology already available can easily be used by anyone to ensure that genetic risks are successfully managed. Thus there is no valid reason for anyone, regardless of alleged potential genetic risks, to either refrain from or be prevented from reproducing.

    1. Thanks, anonymous. Since I wrote what I did above, I have spent some more time defending reproductive rights for consanguineous lovers.

  4. People will come up will all kinds of reasons to explain why consanguineous relationships are wrong or immoral. I just hope that those attitudes change one day. I am in love with my brother, and I feel no shame in that. We have a healthy daughter together. I made sure to see my doctor regularly to make sure the baby was developing normally. As someone mentioned here, there are ways to make sure that genetic risks are managed.
    I do wish that I could tell everyone that he is my brother and how great things have been and how happy we are being parents, but I can't. I know what will happen, so I do what I can like making posts here where there are supportive people. This kind of relationship does have it's challenges, but I wouldn't give it up for anything. To anyone in a similiar relationship I would say this: Don't let fear and misinformation make your decisions for you.

    -Liz Smith


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