"Failure to Thrive" are haunting words to me....that was my son's original diagnosis before they tested & found out he had CAH. In the mean time he almost died. Since he has been on his meds he's been fine. He was a very plump baby, but as I stated in my other post he is very slender built now & has been since about the age of 3 or 4 years old. I would tend to think if a CAH childs meds weren't properly adjusted they would become a "failure to thrive" again...but if their labs are showing normal levels they should be fine...they're probably just destined genetically to be heavier or thiner which ever the case may be. BTW...when you think about genetics don't forget to go back a few extra generations (I have a non-CAH son who evidently inherited a "tall" gene from his great-grandfather).