This is a very interesting article from the Huffington Post about the theoretical "genetic advantage" trans women have over other women in terms of athletic ability. Of course there is a great deal of information out there pointed to the complete opposite. The IOC, NCAA, MMA all allow trans women to compete with other women if they have undergone HRT for a certain amount of time. Also, the fact is that trans women on HRT have comparable hormone levels, muscle mass, and bone density as cis women and after surgery most trans women have less testosterone than their cis counterparts.
Anyway have a read. Interesting stuff here: Do Transgender Athletes Have an Unfair Advantage?