I have checked on this, cortisol cannot be measured in blood when on dex, with pred, you can measure cortisol but it is not the correct or true amount, it shows less than you really get. Could you ask for a repeat test?  I wonder if your daughter’s dose is too high  and although she does have low cortisol, the adrenals are very suppressed so the 17 OHP stays low, I am not sure, but understand your concern.  The ando level is supposed to show over all 24 control, so odd that is on the high side. The only thing I can possibly think of (and it is only my own thoughts) is that your daughter’s dose needs adjusting, may need more at a certain time and less at another. This is why I believe in 24 hour profiles. Would it be possible to get a blood test done at a different time of the day? Perhaps you should write to your daughter’s doctor and ask him to explain it to you in writing, that way you will get a clear answer - hopefully. To be honest, I am not sure I will ever really totally understand CAH! Please keep us posted and good luck. 

Kathy