kengr: (Default)
kengr ([personal profile] kengr) wrote2009-08-20 03:56 pm
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So much for genetic sex being obvious..

.. or even "controlling".

http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2190741

Basically a woman who has been pregnant twice and delivered two healthy kids without medical intervention. And *she* is XY/XO. And one of her daughters is XY.

Tell me again about "XY = male, XX=female".

[identity profile] fayanora.livejournal.com 2009-08-21 12:08 am (UTC)(link)
What is XO?

[identity profile] freetrav.livejournal.com 2009-08-21 01:06 am (UTC)(link)
Basically, the sex-determination pair, normally XX or XY, isn't a pair, just a single X chromosome. The person who has this chromosomal abnormality will have a female phenotype.

The cases where a female phenotype turns out to be XY are generally cases of Androgen Insensitivity Syndrome, where the body doesn't respond to 'male' hormones such as testosterone, and thus manifests as female.

[identity profile] christinaathena.livejournal.com 2009-08-21 03:52 am (UTC)(link)
This wasn't a case of AIS, though, as people with AIS have (often undescended) testes rather than ovaries, and no uterus. This is a very unusual case, since almost all XY females lack ovaries, and frequently lack a uterus as well. In fact, when I first read about XY females, years ago, it was said that it was XY females were invariably infertile. Obviously that's not completely true!

XO doesn't normally result in a typical female phenotype, however. XO females are generally infertile and usually have significant health problems, and lowered IQ. XO is embryonic lethal in something like 90-95% of cases, that is, 90-95% of XO zygotes will fail to reach full term.
Edited 2009-08-21 03:57 (UTC)