David you raise a very interesting deficiency in our gender reassignment approach. I have often felt that there is a real necessity for thorough investigations to be done before such big decisions are made re. gender reassignments.
I was shocked a couple of years ago when I first learnt that it was not standard practice to rule out underlying intersex conditions first. To me this could change the course for some people who are requesting gender reassignment.
Undiagnosed and untreated hormonal imbalances, of whatever sort, (if they are present), should be diagnosed to give the person seeking reassignment the full picture in order to make an informed choice.
As Angela says, an Endocrinologist is the specialist you need to see to sort this out (you will need a GP referral). Ask the Endocrinologist for an ACTH Stimulation Test. The parameters that need to be included on your ACTH testing request form are: 17-OHP, cortisol, androstenedione and testosterone. A baseline ACTH level is also helpful.
If you do have CAH and it continues to be undiagnosed and untreated your wellbeing can be affected in the long run; so your concerns do need to be checked out.
All the best!