Seeking genetic fate

Personal genomics companies offer forecasts of disease risk, but the science behind the packaging is still evolving

“RESISTANT” shouts the title of Lindsay Richman’s post. Apparently, she was elated to learn that her DNA reduces her susceptibility to norovirus infections, the principal cause of the common stomach flu.

So she posted a comment on a discussion board on the website for 23andMe, a company based in Mountain View, Calif.,