Originally Posted by CAVEMAN
Thank you, Nate! A few months ago, I started reading the following book, which I need to finish, and remember the author saying that there has never been a mutation within a human gene that actually was for the betterment of the human. He said that mutations usually cause deformity or retardation. Downs syndrome for example. Check out link to book
Well, the mutation he was talking about actually is a deformity or defect. The body's cell doesn't have the CCR5 receptor which is the only way that the HIV virus has of entering the cell. So, it is a defect that just happens to have a positive side effect.
I know that some people have been born with that defect but I have never heard of someone having the receptor and then something occuring in the DNA to stop producing it.