DNA testing is big business. Millions of people worldwide are finding out about their ancestry and genetic health traits by sending off a spit sample to one of the big consumer genetic testing companies. But what do your genes really tell you? And could genetic testing have harmful consequences for our health and for society? Four experts chart the rise of consumer genetic testing and examine the claims made and our expectations about the results.

Presenter: Helena Merriman Producer: Lucy Proctor

(image: Tube collecting saliva for dna testing of genetic markers. Photo By BSIP/UIG/Getty Images)