Sorry for your troubles
The NF2 genetics thing is just a bit more complex
than the current search for dark matter
Its unlikely that both your father and his sister are NF2
- possible, but unlikely
(If you father was not - it could not link to you ?)
The first question is - do either of them have symptons of NF2 ?
If not, then the daughter maybe a "founder"
- ie there is no genetic link back through the parents
about 50% of all NF2s are "new ones"
(however, were she to have children it could be passed on, 50/50 chance)
That said all of the close living relatives
should have the test
Given the ages (40-50 ?), and no clear indication so far
it is unlikely that there are further links to it
- but only the test will confirm
The test results % accuracy is getting better these days
- more like 75-80% in recent years
Finally it would be prudent for you just to have a regular MRI
scan annually for a few years - for peace of mind ?
Within the clinic that the daughter attends
they should be commencing a genetic search ?
I wish you and all the close family well in this
- the good news is that the there are successful
ongoing trials for an NF2 drug
so it is getting better
Best Regards
Tony