Yes, but companies patent gene sequences without knowing anything about what they do or how to use them, other than they want to charge other people who may want to use them.
The real problem is that you can patent a ham sandwich these days. The more frivolous patents the better for lawyers specializing in patent barratry.
I used to think so, but our resident patent attorney on FR has convinced me otherwise. Patents were loose in the 1990s but have tightened up significantly.
I don't understand how you can patent something that exists naturally (gene sequences). Perhaps they patented the sequencing technology or gene sequences that they actually spliced themselves?
IIRC, you have to prove a practical application/working model before you can patent.