Well, I made a post in Vanessa’s thread that I totally was saying I’m not gay, but when I ended that post with “I like my mates with an X and a Y”, I had no idea I was stating I wanted a man.
Yes, and we call those "Abnormalities" because they are so many deviations away from a statistically "Normal" person that calling them rare would be an understatement.
So, viability and statistically speaking, the only ones that matter are XX and XY. That doesn't mean round up all the "Abnormal" ones and hold a book burning with no books, it just means teaching intro science to people with the presupposition that XXY and XYY are statistically relevant is a silly thing to do. They should be discussed in the same lesson as Autism, Downs, and other genetic abnormalities.