There are common diseases you should worry about and rare diseases you shouldn't worry about. A factor of 2 does not move Crohn's from rare to common. The difference between a 70% chance of dying of heart disease and a 30% chance sounds pretty big, but what would you do differently? Either way, it is a big chunk of likely mortality. A factor of 2 is unlikely to change the cost-benefit analysis of actions that might protect you from heart disease. If such an action is useful, it is useful for most people.
Some rare genes do move diseases from rare to common. A broken BRCA (1 in 10k) moves a woman from a 10% chance of dying of breast cancer to an 80% chance of dying of breast cancer, and dying at a young age. Mammograms are valuable for the second woman and not for the first. Some women have prophylactic mastectomies. But if you ask Myriad to test your BRCA, in addition to this useful information, it will also talk about minor variations with useless effects on the risk.
Thanks for your reply.
Do you think it would be fair to say that for rare diseases (that are not determined by single loci mutations, like Huntington's or BRCA, as you described) it's silly to get a test because a small movement in your risk profile is meaningless in that it wouldn't impact your treatment or behavior in a meaningful way?
Could you explain what you mean by:
Either way, it is a big chunk of likely mortality
Do you work in a related field? You explained this rather concisely, thanks.
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