Which Recessive Disorder Is Most Common?

Cystic fibrosis is one of the most common inherited single gene disorders in Caucasians. About one in 2500 Caucasian babies is born with CF and about one in 25 Caucasians of northern European descent carries the gene for CF.

Why are recessive disorders more common?

Recessive disease mutations are much more common than those that are harmful even in a single copy, because such "dominant" mutations are more easily eliminated by natural selection.

Are recessive disorders common?

It's estimated that all people carry about 5 or more recessive genes that cause genetic diseases or conditions. Once parents have had a child with a recessive trait or disease, there is a 1 out of 4, or 25%, chance that, with each subsequent pregnancy, another child will be born with the same trait or disorder.