If you are talking about Reborn, maybe once or twice.......or at least they make small difference in Relationship points (getting extra point for Adrien if you are gender-neutral, since Cain called you both cute; getting an extra point for Samson if female, though it evens out later).
Ah, okay. I wanted to pick the gender neutral character because I like their design better than the white male's. Plus I've used the white male so often. Still might go with him if the gender does affect anything.