Woah there. Genetic changes aren't heritable. Not when they're done in body cells that is. There's a difference between the body cells and the sex cells aka. sperm and eggs. You can change the cells of the mothers or fathers body however you like but it won't have any impact on the offspring. You can only make heritable changes if you modify the sperm or egg cells. And genetic changes being "contagious" makes absolutely no sense.