Hi Lucy... I'm glad that Jennifer provided a bit of input. I did some digging on the net as well as through stuff I've accumulated over the past 12 years. I must admit that I did not come across any reference to boys with 21 hydroxzylase deficiency as having problems developing in the expected way for a male. While your description of CAH indicators fell in line with what I have, no reliable sources that made reference to small testes as an indicator of the condition in CAH boys with 21 hydroxylase deficiency.(I did find one source that I considered unreliable - see below) Maybe some of the parents with CAH boys will correct me if my info is wrong. I copied this one for you. Excerpts from.... http://bspe.shef.ac.uk/NN/CAH21OH.html "Since boys are already masculinised by their testes they show no abnormality at birth." "Normal development in all respects, normal fertility and a normal life-span without restrictions can be expected. If the correct doses of these steroids are used, there are no side-effects whatsoever as the treatment is merely replacing the normal secretion of the adrenal glands." "If too much hydrocortisone is given it causes weight gain and slowing of growth; too much fludrocortisone may cause high blood pressure." If your son's meds are too high you would expect his growth to be curtailed as well having some of the other problems listed above. If your doctor keeps a growth/ height, what percentile is he in? How often does your son get blood tests? 90-95% of male testosterone is made in the testes not the adrenals. It is for that reason that boys with 21hydroxylase deficiency will develop as expected ....as long as they are receiving the correct abount of replacement meds. If you are certain that the medication is not causing oversuppression, has the doctor tested your son for other disorders? Is your doctor absolutely certain your son is the type of CAH with 21 hydroxylase deficiency? I asked before if your son's doctor was a pediatrician, endocrinologist or a ped endo. I know only far too well the difference. After taking three years to get my own child diagnosed, I can tell you a good ped endo is worth her/his weight in gold....actually they are priceless. *Note - I did find one source that made reference to small testes in CAH boys, but it was a student paper on hermaphrodites posted on the net - hardly a reliable source. ( Frankly it reminded me of the TV shows of late on this subject that so frequently are all hype)