"There's no other place where we so quickly divide humans into two categories as sex."
---- Gerald N. Callahan,
aqui:
http://www.salon.com/mwt/feature/2009/07/07/xx_xy/index.html
"There is currently no known cause for Turner syndrome, though there are several theories surrounding the subject. The only solid fact that is known today, is that during conception part or all of the X chromosome is not transferred to the fetus."
--- Wikipedia
