Dalrymple explains the considerations involved in genetic screening decisions:
Two obvious questions arise: is additional risk clinically as well as statistically significant, and if the risk is known can anything practicable and tolerable be done to reduce it? There is no point in avoiding a risk if to do so makes your life a misery in other respects. You can avoid the risk altogether of a road traffic accident or being mugged on the street by never leaving your house, but few people would recommend such drastic avoidance.
When people tell you that something x causes a twofold increase in the risk of y, you need the absolute as well as the relative risk in order to know whether it is really worth avoiding: for on the absolute size of the risk depends the effort that it is worth making to avoid it. Moreover, you also need to know the size of the risk-reduction brought about by the avoiding action, and again the absolute as well as relative figures are necessary to make a decision.
As if this were not complex enough, people vary so much in their values that it is usually not possible to give unequivocal advice. A risk that seems to one person to be worth going to enormous lengths to avoid may be deemed trivial by another. No one can speak for anyone else.
Then there is the question of cost.