Not an expert, but there is a lot that is probabilities. E.g. many genes play a part in disease, so changing one set may get you a risk reduction but not full p

Not an expert, but there is a lot that is probabilities. E.g. many genes play a part in disease, so changing one set may get you a risk reduction but not full prevention. The other issue is epigenetics. Gene expression is regulated by various factors and that gene expression can be passed between generations. https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Epigenetics