But those are three of the most significant of the possible BRCA mutations, no?

after you have the dna mapped out, how can you patent looking for a pattern?

or is there a completely different way of mapping specific genes?

I have done 23andMe and had my full genome sequenced. Unfortunately, we are still in the early stages of understanding our genome and there is often little of medical importance revealed.

The most significant of the "something really bad and unexpected" are the risk factors for Alzheimer's and Breast Cancer. I believe that there are certain markers for both those diseases which could reveal that you have a much higher lifetime risk (for some cases of breast cancer, >50%), which is obviously scary. Don't quote me on this, but I believe in both situations you are very likely to have had some family history in these diseases, so it should not be a total surprise. And if you have a family history of breast cancer, you should be getting Myriad's full BRCA test (see my other post). I would probably look into a clinical test for Alzheimers too if I thought I was at risk.

There are a few other diseases that also have big impact (>50% lifetime risk), but they are rarer, and I'm not sure if there are any where you would have had no family or personal history to clue you in on the possibility.

The vast majority of the diseases 23andMe reports on give you very little actionable data. For example, it might say I have a 2x risk of prostate cancer, from a background risk of 2% chance to a personalized 4% chance. I view that as pretty unhelpful. Furthermore, it's based on SNP-associations currently known. It's possible, I have another SNP that's associated with a .25x risk, and therefore I actually have only 1% chance overall, i.e. half the general population's risk.

23andMe can be useful for other reasons. For example, it will tell you if you are a recessive carrier of certain diseases, which is helpful if and when you decide to have children. It's also fun, has ancestry info, etc.

Sure. Of the high penetrance mutations 23andme tests for, I don't have anything really bad. I think it's worth knowing for most people, because of minor things you can do to alter your risk. For example, people with the bad version of the high risk Alzheimer's gene (ApoE4) probably respond better to paleo-esque diets and intermittent fasting than the average person.

I have. I find that it's very valuable to know what you're at risk for so you can plan appropriately. Of course, I was not at-risk for anything serious so it was not hard for me to cope with the results. I can see how coping with very bad results could be extremely difficult though... it's a tough choice if you are a more emotional person.

I think that a lot of programmers are probably more cold and logical in their thinking (like me) so it was a pretty easy choice for me.

My wife is a lot more emotional and I have tried to convince her to get 23andMe but she refuses because she doesn't want to know.

The government also pays for screening imaging, MRI included (this is one of the rare situations where MRI is used as a screening tool). This is probably significantly more expensive than the gene test.