Why would natural selection not work with turner syndrome?

Question

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Answer 1

It does work, just not as obviously as it may seem. Turner Syndrome is caused by a non-disjunction event which leads to a female that is missing part or all of one of her X chromosomes. This is caused by an inefficiency in one of the steps of meiosis. Since meiosis is performed by a large number of proteins and enzymes, Turner syndrome exerts selective pressure on those genes which code for them.

Imagine a scenario where a population of individuals had very inefficient meiosis were 1 in 10 girls had Turner syndrome. Then introduce some people that have very efficient meiosis and only 1 in a million girls had Turner syndrome. This new group would have more healthy girls which could in turn continue to pass those good meiosis genes to their children. The other group would use a lot of time and resources on children who could not reproduce (which is a part of Turner). Over time the good meiosis genes would be selected for.

Edit: Dana B is mistaken.

Those women who  have a child with Turner syndrome suffer a loss of fitness because the child with Turner syndrome will not have any children and will not pass on any of the mother's genes. Natural selection has led to a meiotic process in which events such as Turner syndrome are infrequent, however, this could not have happened unless there was some sort of selective pressure.  

The selective pressure acts to make meiosis more efficient, which in turn makes the sort of accidents that cause Turner syndrome or Down syndrome less frequent. The heritable traits that are acted upon are the components of meiosis.

Answer 2

Natural selection is the theory that if an organism has a trait that causes it to be less successful in surviving, competing for resources, or reproducing, then it will pass that trait on to fewer offspring and thus the trait may eventually die out.  However, it assumes the trait in question being one that is inheritable, in other words one that must be present in the parent and can be passed to the child. Girls with TS are born to healthy, "normal" parents because of a random accident in the formation of an egg or sperm.  Therefore, the fact that women with TS cannot produce children does not in any way affect the rate of women being born with TS, so the "trait" of TS does not die out.