Every single disease _will_ have a genetic “cause”.
Every… single… one… because we are all built on genes.
So there is some hypothetical enzyme that adds atoms to a colorless molecule (ClearMol. CM) to create a blue color(BlueMol. BM) and that blue color gives us blue eyes.
Hypothetical: There is a pesticide(P) that is acted upon by this same enzyme. (Every single enzyme cross reacts with other chemicals. This is why there are enzyme inhibitors and medical side effects to drugs.)
Back to our hypothetical — When our human [blue-eye]enzyme acts on the pesticide it does the same thing it would normally do and adds the same group of atoms — but to the pesticide (PesticideBlue PB). Now the changed pesticide PB has different biological properties one of the original pesticide that the companies tested and PB causes disease. This is all hypothetical but …. After years of scientific investigation the enzyme for blue eyes would be identified as the cause of the disease. People with blue eyes get this disease and no one else does.
Also you could chemically (medically) block the function of the blue-eyed enzyme and prevent the disease.
Ergo The genetic cure for this “disease” then would be to “cure” us of the gene for blue eyes. Or chemically inhibit the function of the enzyme. Wow a new drug you could sell :-). This in my opinion is the danger of designer babies and really most drugs.
In my opinion it would be the pesticide that we should cure ourselves of.
Learn about your world.