This would be a concern if DNA was something secret like a password, but it isn't, it falls off you all the time in the form of hair and skin cells, so if there was something valuable in your DNA, your employers could get it easily anyway. And if your DNA was useful to insurers you would pay yourself for them to get it, because knowing that your risk of dying from certain disease is higher is also required for preventing that.

In general trying to keep DNA secret to prevent discrimination is a losing game, a better strategy is preventing discrimination itself, which we already have to do for DNA variations that have visible manifestation. Moreover if the number of people who need protection from discrimination increases, we'll get better at preventing it, which would be useful for the people who are being discriminated now.