The federal government recognizes people who identify as transgender as having a mental illness. Now listed as "Gender Identity Disorder", people who wish to undergo surgical or hormonal treatments are discriminated against due to the listing.
It is also in effect that transgender individuals are NOT protected under the anti-discrimination rights as gay/lesbian/bisexual people. (i.e. you can be fired for being transgender and not be able to fight it as discriminatory)
This petition is focusing on removing 'Gender Identity Disorder' from being considered a personality disorder.