Its a very broad term and some autisms aren't an advantage in anything, but certainly many autists are a gift to humanity.
They don't tend to procreate, though. I think it wil remain an occasional benevolent anomaly. Rather than the genes, the work of autisms is sure to have a substantial part in humanity's work as a whole.
Autisms is generally considered to carry with it a lack of ability to empathize. Sometimes a person appears to be autistic because he is too empathic, and isn't able to push out his inner world in a reaction.