If I may, I could offer an example. The inherited arrhythmias, such as long QT syndrome, are a good example. Let's say one's parent has the condition. Then one is at a 50% risk to have it. A genetic test can say yes or no as to whether that person has a predisposition to potentially life-threatening arrhythmia that can be treated with anti-arrhythmic medication and sometimes an implantable defibrillator.
If somebody refuses to have that genetic test simply because they're afraid of employment or insurance discrimination, they forgo that treatment. They don't discover whether they need that defibrillator. It makes a very real difference.