Right
I have been saying this for years, even in my genetics classes in college much to the professor's chagrin.
We have the "genes", whether they are active or remain dormant depends on many factors including primarily our thought, diet, and environment.
Of those three, thought may be the most powerful... I am still investigating that.
Not having enough
Iodine and\or having too much toxic wastes including fluoride that apparently function to shut down enzymatic and/or hormonal pathways can most certainly alter genetic expression. If it did this in my father and mother before my conception and then during gestation, I most certainly have a genetic difference from them and a predisposition that may appear on the surface to be genetic, but in fact is just a "symptom" and not the root cause.
This is only one such example of a possible infinite number of possibilities that illustrates an influence of genetic expression.
Olree gets into specific minerals that can and do cause genetic expression shifts.