It takes a recessive gene from BOTH parents. This disorder is detected through blood tests....I'm not sure WHAT the endo was talking about when he refused to do the testing because it was "so painful". They can get all the blood they need from one blood draw. Actually in some states, it is part of the Newborn Screening. Check to see if your state (if you are in the US) is one of them; if so, double-check with your pediatrician's office on the results, or request they be redone. I don't think I would wait for symptoms....we didn't find out until our daughter was almost 4 years old.....her bones had already grown to age 7. She's on cortisol now and is just fine. E-mail me if you have any questions. :)