I am a 31 yr old female with duplex kidneys. I have vast knowledge of this rare physicality, but I am curious as to why neither one of my parents, siblings or immediate family have this condition. But here is the kicker....neither do any of my 3 children. I cant explain this. I am not adopted so I have no answers. If someone can give me some info or point me in the direction to help, I am most grateful!