This is really interesting. I have a 9 month old with CAH. My husband is Hispanic (his dad is Caucasian and his mom is Mexican). I think many (most?) people with the mild form of CAH are never diagnosed. I wonder if a person inherits a recessive gene for the mild form and a recessive gene for the severe form if they will have the severe form? Because then what Chris was saying really makes sense. If one parent has a recessive gene for the severe form of CAH and the other parent has mild CAH (so carries two recessive CAH genes) the chances of such a couple having a child with CAH are actually 2 out of 4 instead of 1 out of 4 (did I do that right?).