Comment by JunkDNA | Hacker News Reader

Comment by JunkDNA | Hacker News Reader

This is a fantastic article that is extremely well written and does an excellent job of conveying the science. I think one of the more interesting side-effects of cheap DNA sequencing tech is that we're starting to find out that while any individual rare disease is rare, in aggregate, rare diseases are actually quite common. This also means that many common diseases (especially ones whose causes have eluded researchers) may actually be a constellation of rare diseases that look the same from our 20,000 foot view.

Fortunately, cancer is one such disease and it has the advantage of a healthy funding stream plus significant public mindshare. I suspect many of the techniques we are just starting to use to discover the causes of cancer and personalize therapy will start to be applied to rare diseases. These diseases will effectively get to capitalize on all the "infrastructure" that we've been working on without having to bear the cost burden of the inevitable 10's of thousands of dead ends that come with this kind of work.

To expand on your comment "rare diseases are actually quite common", I was struck by this in the article:

    More than 7,000 such diseases exist, afflicting a total of 25 million to 30 million Americans

That's almost 10% of Americans! I suppose this shouldn't have been surprising given the Birthday Paradox [1], but the ~1/10 statistic puts things into perspective for me.

[1]: http://en.wikipedia.org/wiki/Birthday_problem

That means most of them must be mild. Because, clearly, 10% of Americans don't have something as serious as FOP. There's probably a long tail of increasingly rare and increasingly mild diseases, so that the cutoff is arbitrary.

Yes, I'm not sure that they're diseases, per se.

I think a better term should be found, perhaps 'phenotypes' or 'variants'

Mild, or self-limiting or otherwise transitory. I know (closely) three people in two different countries who have a 15/100,000 disease that is self-limiting.

It wouldn't be very surprising to learn that every single person has some kind of genetic defect -- perhaps dozens -- but usually the compensatory mechanisms are strong enough to mask them, at least while you're young and strong overall. It makes a lot of sense that health should be a spectrum or a kind of dynamic equilibrium, rather than a binary on-off condition.

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