🚀 go-pugleaf

In article <1957@trantor.harris-atd.com> hnewstrom@x102a.harris-atd.com (Harvey Newstrom) writes:
>
>In humans the Y chromosome produces males, while its lack produces females.
>Thus, XXY is male, while XXX is female.  XO is female, but I don't think any
>survive in humans.

   XO is female, but they do survive in humans - the resulting abnormal
condition is called Turner's syndrome.  The phenotypic characteristics
of Turner's syndrome are short stature, wide, web-like neck, poorly developed
breasts, and immature internal sexual organs, and sometimes mental deficiency.
I used to work with a woman whose daughter-in-law had Turner's syndrome -
she was short, but not really "abnormal" in appearance (whatever that means).

   What surprises me a little is that many organisms are pretty tolerant
about wide ranging variations in number/distribution of the sex chromosomes,
but such variations are definitely NOT tolerated well in the autosomal
pairs.  Trisomy-21, familiar to all as Down syndrome, is the only common
such aberration, and it involves a fair amt of impairment (depending on the
individual, of course).  My genetics textbook lists 2 other trisomic
abnormalities, trisomy-13 (1/5000 births) and trisomy-18 (1/10000 births).
It's my understanding that these 2 conditions have extremely high mortality
rates, and surviving victims are quite severely handicapped.  

   Warning - WAG follows:  Can it be that there isn't such a big deal about
our sex after all?  :-)
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  Sue Miller         {decvax,hplabs,amdahl,nsc}!sun!sunburn!gtx!sue
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