[Flyndaran]

I, my life mate, and our housemate all have the gene that makes cilantro taste like hand soap. My first experience with restaurant salsa having it made me think they failed to wash the dishes properly.

My pre-diabetes olfaction made me able to smell a few oddities of humans most don't know about. All men except the few gay guys I met had a mildly irritating scent I can't describe. All bisexual women, and one hetero woman I met had a very pleasant scent I also can't describe. (Yes, I joked that she just hadn't discovered that part of herself yet.)
Strangely, I have never been able to smell rotten milk. Even horrific chunky months past expiration glop has only the barest hint of "sweaty" odor to me then and now. That would be interesting for a PC with a super sense that can't detect something obvious to mundanes.

So the potential for perks/quirks for those with enhanced senses are downright boundless. And as the cilantro thing shows, it's certainly possible for anyone to have odd gene variants.