Alot of diseases, esp. the rare ones, doctors have no clue. This is autoimmune, and there may be no genetic component to it. Many things seem triggered by some other event like viruses. I’m not going to tag it as in-breeding.
It is human nature to believe that we know and understand much more about the human body than we really do.
The explosion of “chemistry” throughout our society likely has much more impact than we know on our health with new toxins and compounds emerging weekly and we don’t give enough thought to this.
We have deployed a vaccine to hundreds of millions of people that we do not fully understand and you are not allowed to discuss it.
We know genetics can play a major role in many diseases, but we are only scratching the surface of what it means.
Modern medicine, like many pursuits, is focused on $$$$ and there is little money in preventative care versus catastrophic care so most research follows the $$$$.
The last one is a major disappointment for me.