Transsexuality is a manifestation of spontaneous human diversity
A transsexual is an 18 month old child who says, "I'm a girl." But nobody believes her. For some reason, adults feel compelled to override that child's inner voice. They try to turn their little girl into a boy.
Humans were designed for diversity. There are numerous natural processes that work during fetal development to maximize diversity--to assure that each individual is born with a unique set of gifts, challenges and perspectives. Transsexuality results from those natural processes.
...The purpose of life is to discover one's inner voice; to gain strength from the challenges; to use one's gifts for the benefit of humanity.
Transsexuality isn't a disease or an aberration. It doesn't mean the natural processes broke down or failed. It doesn't need to be cured. The problem with transsexuality is social misunderstanding. Parents and society in general try to force a transsexual to be what they're not.