Sun 11th January 2009, 5:44am
QUOTE(One @ Sat 10th January 2009, 7:54pm)
How strange, I was just about to cite a recent straight dope column myself in response to this:
QUOTE(lolwut @ Sat 10th January 2009, 4:12am)
It must be extremely difficult for transsexuals; I understand that. But I can't personally relate to why one would have a strong desire to change sex. Iit's not something that... you know. I just don't get it at all. If you're born XY, you'll always be XY. There's no point in having a 'sex change' if you'll always be genetically male.
A small but non-zero number of humans are born genetically male, but developed female.http://www.straightdope.com/columns/read/2782/switch-hitter
See also this Time article
about the woman mentioned.
Intersex conditions are shockingly waaay
more prevalent than people are aware of; somewhere between 1 in 500 - 1 in 2,000 live births can be classified so. Obviously, it's only in relatively recent times that women with CAIS, for example, could be diagnosed at all
. Before decent karyotyping, they were just women with fertility problems and not XY persons with a genetic insensitivity to androgens. We just didn't know it and neither did they. There are plenty of folks roaming about with dodgy karyotypes - we meet them all the time - but we (and largely, they) don't know it.
As for XY, versus, XX - how about 47XXY (Klinefelter Syndrome)
, 45X (Turner Syndrome)
... and so on. These are all the 23rd pair sex chromosome related anomalies. There are also other chromosomes that can cause problems and there also are instances of other non-monosomy/trisomy conditions like Swyer Syndrome
which can produce XY females. There are also cases of XX males (de la Chapelle syndrome
) , too, who are genetically female.
Then there are people who are 'immune' to male hormones
, to varying degrees. There are also dizygotic mosaical 'persons'; basically twins with a single body. They can be both XX and XY, depending on where you take your tissue samples from
This is extremely rare. Check out this fascinating picture of Blaschko lines
in a mosaic individual. This basically shows the patterns of cell migration during fetal development and both sets of cells are showing up as 'streaks'.