As a teen I was told I suffer from CFS (Chronic fatigue syndrome), brought on by being anemic and two bouts of mono. At age 62 now, I wonder if it was narcolepsy the whole time. There was no testing for this back then.
Auto immune disorder is genetic But there is also triggers if you have the genes in place or lacking
It is genetic as far as I know I have neuropathy that did come directly from the prenicious anemia though so it could have contributing factors.
Very well could have been was even misdiagnosed in the 2000s so many times