Is transsexuality a sin in Islam?

Islam has tight-as-a-drum attitude and practice towards sexual vices in general, as in Biblical days, prostitution and related offenses are a capital crime in some Islamic countries. Lesbianism is rare and might be also considered a life-threatening vice (by the authorities.) An Imam is a sort of Islamic Judge/official and also a minister. Like many religions, they don't tolerate sexual variation.