The other levels could be a few things. It could be Plasma Renin, ACTH, antrogens, or electrolytes. The most likely is the Plasma Renin level. The 17OHP level is always better to be a bit on the high side so that it doesn’t lead to being oversuppressed. What dose is your son  on and what are his 17OHP Levels. I have been having Blood tests for 33 years and in the last 18 months I have been getting 17OHP AND PLASMA RENIN TAKEN TOGETHER to check my doses. Ask the ped endo about all the tests that are taken and ask if possible to have a copy of the results. I hope this will help you.

Stay healthy, Stay Strong

jayne