At this point, we’re beginning to think previously unthinkable thoughts like “what if the hypothesis the last 20 years of research was based on (beta amyloid plaques)is just totally wrong”.
we’ve made drugs that reduce plaques. they don’t ameliorate the disease.
https://www.upi.com/Health_News/2018/04/11/Researchers-find-...
I know we all see at least half a dozen of these a year, but nobody can say in advance how they'll turn out (unless it's just obviously badly designed research). This line of inquiry certainly seems to have some promise.
If you can conclusively say "these n<5 genes are exactly the things that make people 50% more likely to develop a disease", you're cooking with gas.