Genetic testing..why does it all take so long??

[DNAP]

Quick background. Daughter now 9 and has had health issues since birth, similar to CF, but sweat test borderline. Has had about 30 hospital admissions upto now, and sees multiple specialists on a regular basis. All in all, you would think we would have some answers by now, but it is all just so frustratingly endless and laboriously long! She has had genetic testing for primary immune disorders, and although they took 18 months to come back, they don't think the mutations they found, reflect her presentation. So we're back to the drawing board..again! Now they want to do more expansive genetic testing, and this has to be approved by various tiers of specialists..we'll hear if she's been accepted, hopefully by Spring. And then once she's accepted, it could take upto another 2 years. 2 years?!!
I just don't understand why everything here takes so long? My cousin's child in the US was diagnosed with CF. They didn't just rely on sweat tests, ( for which his was also borderline), they did DNA testing for all known mutations, at the same time. And he was found to have a mixed mutation, one which was quite rare, so the presentations with this can vary quite a lot.
All in all, they had all the tests and his diagnosis within weeks. Yet this is not even offered here, and borderline test results, are not given any element of doubt, which is terribly frustrating when you are in this situation.
We've just tried to express our frustration at not having a diagnosis after all this time, and their attitude is that it really wouldn't change anything, as her treatment would be the same. But of course having a formal diagnosis, means so much more than this, and I am sure there are many more people in this same situation.
What makes it more frustrating, is that there are genetic tests you can actually purchase online, including a whole array of carrier status conditions, including all known CF mutations. And you can get your results back in 2 weeks! Yet in a renowned tertiary care centre hospital, this is seemingly not possible?! I appreciate there is far more to it than just cherry picking a few tests, and I know there has to be a clinical aspect of judgment, but why does it all take this long, and why is actually having a diagnosis, when they know that something is wrong, not given the importance it should deserve?
Does anyone have similar experiences? Would love to hear from anyone who has. Thank you!

Not sure about the delays with the specialists, etc, but I used to work in a genetics lab. If your DD is being tested specifically for rare CF mutations then there's only one lab in the UK that offers the test, and the turnaround time for the lab when they've received the sample is 40 days. Before that, the blood needs to be taken and DNA extracted (this will probably be by a different lab than the one doing the testing) and sent away to the lab that actually does the testing, which can take up to a month alone.

If she's having a bespoke panel then the genetic testing itself can take up to a year, because primers will need to be designed and processes validated.

Also genetic labs in England are going through a restructure soon so things will probably be delayed by that. Sorry to not have a definite answer but I hope it turns out to be a bit speedier for you and DD

Thank you, that is helpful to know. Given that there is only one U.K. lab that tests for rarer cf mutations, and that takes 40days, I am presuming we should be wary of any privately accessed lab service, that is offering carrier status results within 2 weeks?!
As for the rest, yes I believe the test process they are proposing, is where the entire genome is looked at, and we are told that this can take years. Thanks again for your reply.