I am not a medical health professional and any comments I post are not intended, nor should they be construed, as medical advice. If you believe you are experiencing a medical emergency, dial 911 (where applicable) or contact proper emergency service personnel.
DNA in health and disease https://isogg.org/wiki/DNA_in_health_and_disease
The above ISOGG link is a good starting place.
I would add some cautions: autosomal DNA testing – AncestryDNA, 23andMe, FamilyTree DNA (FTDNA), MyHeritageDNA, LivingDNA, etc. only look at a small portion of our DNA. Next, as much as some medical experts want to think they have documented all the known markers for a particular disease, they often only look at a handful of markers for diseases which aren’t that common. No telling how many markers they are missing at this point in the game.