Yes it is common to have one or more family members with CAH. Both my boys have SW CAH. They are 3 and 6 and doing great. You will be able to handle it, it seems so scary and hard at first but you and your kids will be fine with good medical care and supervision.

I do not know of any conection with seizures, but some while back there was someone else that had a child with that type of behavior.

Good luck.