Hello Misdee, I have posted on your other thread in the past.
Ds is 6 and a half and still has no diagnosis, the agonising testing, and inconclusive results has become less agonising over time.....but I still get a flutter in my chest when I get an unexpected medical looking letter, thinking it could be results from one of the studies he is involved in. (this has literally just happened. - heart thumping, shaky hand....it was a physio report!)
It can be a struggle, but you can definitely access support without a diagnosis - ds gets DLA, has a raft of therapists and attends a sn unit in a mainstream school (with a full EHCP). He has additional needs,, and complex health issues - just because there is no hook to hang these on, doesn't meant they aren't there.
When you see the geneticist ask about participating 100,000 genome study - which would give your dd access to the latest genetic testing
Be warned though, even with extensive genetic testing (micro array, FISH etc), everything may still come back 'normal'. This has been the case for ds, but his geneticist still thinks there is a genetic condition behind his problems, it may just not have been discovered yet!
If you don't want to fill out the forms, have a look at SWANs Facebook page, their forum is very active.