I think you know the bishops’ position on this issue, so you seem to want to claim their authority on that issue but not this one.
Religious leaders pen open letter speaking out against transgender identities
While I sympathize with the point the Bishops are trying to make, they will need to clarify the following statement from the letter you cite to conform to JPII’s very clear teaching that
there can be no contradiction between science and religion.
http://inters.org/John-Paul-II-Academy-Sciences-October-1986
As stated, the belief being expressed in the letter is scientifically false.
We come together to join our voices on a more fundamental precept of our shared existence, namely, that human beings are male or female and that the socio-cultural reality of gender cannot be separated from one’s sex as male or female.
http://www.usccb.org/issues-and-act...fense-of-marriage/created-male-and-female.cfm
This statement is in error, because human beings are not ALWAYS created either male or female. One cannot ignore the instances of human beings who are naturally created as
both male and female, as in the case of human beings created with Klinefelter syndrome.
Klinefelter syndrome - Google Search
A person with Klinefelter syndrome may have both ovaries and testicles. They are born with a penis, but as they mature, they naturally develop breasts and increasingly feminine bodies. Nearly all begin life living as boys, but then their bodies begin to dramatically change after puberty, some find it to be psychologically and socially more consistent to switch and adopt a female gender identity. While rare, such cases objectively demonstrate that God is not restricted to the binary distinction of biological sex as either male or female, and that gender identity is to some extent fluid. The theological significance of this has yet to be satisfactorily explored by theologians, but it will need to be at some point as the weight of scientific evidence forces the church to reevaluate its doctrine as stated.
If what the Bishops say is true, “that the socio-cultural reality of gender cannot be separated from one’s sex as male or female” then where does that leave a person who is created BOTH male and female? See the problem?
Per Genesis, God certainly created people who are male or female, with a gender identity that matches their sex and is biologically determined. However, God obviously did not begin there (i.e., the original Adam was both male and female) and clearly did not end there.
I personally look forward to clarification on this issue, because one of the things that makes me Catholic is the process by which the Holy Spirit guides the Church in the development of doctrine towards ever greater truth.