I have to disagree. If I had heart disease, for example, that is a risk factor for an early death, and thus an early payoff on my life insurance. It should cost me more in that case. Now, if you take care of your condition, as you say, THAT should also be factored in, but if your Type II diabetes is a risk factor for living a long life, it should result in higher premiums. If we could determine with certainty that I would die in 2 weeks, and you would live 50 more years, who should pay higher premiums?
Ahhh...but it isn't (when controlled through diet and exercise). So it shouldn't result in higher premiums.
Your heart disease (hypothetical, I hope) is far more of a risk factor that does not respond as well to "clean living" as does my risk factor. These are all things that need to be factored in when DNA becomes an issue in determining premiums and if the laws governing DNA use by insurers are put in play. I do believe that insurance companies have already lobbied for the rights to use DNA sampling for just these purposes.