Would you like your child to be called a deviant at school? Surely, if you had a child, he would “deviate” from the “norm” on some scales. We all do.
Yet as I said, the word deviant has a pejorative aura. You cannot deny it. Pointless to use the dictionary. Call Sarah Palin’s adorable child “retarded” to her. See what I mean? Words have connotations as well as definition.
Sexuality is a behavior. Downs has a physical cause. Your attempt to equate the two is disgusting.