The John Williams NewsClick: Surprise! You have a half-brother!

FILE - In this Thursday, Sept. 29, 2011 file photo, a scientist works with DNA samples in a New Orleans laboratory. On Wedensday, May 27, 2015, the first report from a big public-private project to improve genetic testing reveals it is not as rock solid as many people believe, with flaws that result in some people wrongly advised to worry about a disease risk and others wrongly told they can relax. (AP Photo/Gerald Herbert)

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