It’s interesting.  My daughter who isn’t even a CAH carrier had early puberty (she started at about 8) and now she has PCOS.   I would think (I’m really going out on a limb here) that if your son had CAH he would have started with pubic hair, acne and body odor, before going into puberty.  That would be because the androgens would be coming from the adrenal gland and not the testes.  Of course there’s no reason not to test him for CAH.  My daughter’s initial workup included the preliminary 17-ohp which was so low that they didn’t follow up.  I also don’t know how he could be so obviously in puberty without high testosterone levels.  My son’s testosterone levels have been high for 2 years (about 40) and he isn’t in puberty yet.  They also have a puberty stim test.  I think they have to give them a shot on one day, and then a blood test on the next day.   It’s all really so tough on them!   Maybe his levels would be elevated on that test.