wade thru the 'stickies' at the top of this forum?
Here is one:
http://www.eprom.pitt.edu/UL_media%5C149993684.pdf
another is:
http://www.aafp.org/afp/980215ap/poncelet.html

Reading these, you can see that there are many, many paths to take for a diagnosis...at the most you actually GET a diagnosis [name], but, overall TREATMENTs are common for all. Get the treatment first..then worry about the latter.

I myself have found I might actually have a 'heridetary' part to my diagnosis, found by a set of other conditions I have been blessed with. Yet all-ALL of my docs don't seem concerned about going that extra step....even tho when I do reach 'medicare age' it could make a BIG difference in my access to IVIG. Go figger? You do have to learn a 'new language' when you have the kinds of 'stuffs' we have...we have to learn to use that language well to get what we deserve and need. Hope this helps! - j