18 September 2011

One sperm donor has 150 offspring

Today there are 150 children, all conceived with sperm from one donor, in this group of half siblings, and more are on the way. “It’s wild when we see them all together — they all look alike,” said Ms. Daily, 48, a social worker in the Washington area who sometimes vacations with other families in her son’s group.

As more women choose to have babies on their own, and the number of children born through artificial insemination increases, outsize groups of donor siblings are starting to appear. While Ms. Daily’s group is among the largest, many others comprising 50 or more half siblings are cropping up on Web sites and in chat groups, where sperm donors are tagged with unique identifying numbers.

Now, there is growing concern among parents, donors and medical experts about potential negative consequences of having so many children fathered by the same donors, including the possibility that genes for rare diseases could be spread more widely through the population. Some experts are even calling attention to the increased odds of accidental incest between half sisters and half brothers, who often live close to one another. 
Further discussion of this interesting situation at the New York Times.

3 comments:

  1. Surely the simple solution is to limit the use of a single donor's sperm.

    We have only to turn to animal breeding using artificial insemination to get an idea of what can happen. I suggest looking up HYPP in Quarter Horses, which likely originated from ONE stallion, and now is ubiquitous. http://www.bringinglighttohypp.org/

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  2. I wonder what it is about those few donors that they're chosen repeatedly. A resemblance to Brad Pitt, perhaps?

    HYPP does trace back entirely to one stallion named Impressive, and possibly to his full brother. While the situation among humans is not nearly as dire as what the Quarter Horse breed is now facing, it's an interesting case study.

    Top quality stallions often sire 150 foals per year (that's close to the biological limit, I believe). There are many horses in the Impressive line that were successful enough to have hundreds of offspring of their own. And like European royalty, the highest quality horses are often inbred.

    Horses are mature and ready to produce another generation at four years. Impressive was a 1968 foal, so that gives us ten generations maximum to spread HYPP to the extent that all three million present day Quarter Horses are potentially carriers. (Impressive is more commonly four to eight generations back for present day horses, I think.) I'm sure somewhere out there can do the math better than I can.

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  3. and that took them how long to think that out ????? jeez !

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