Where do you come from? Tracing your ancestry in the USA is one of the most popular hobbies along with gardening and golf. TV is awash with advertising for the do-it-yourself genetic testing kits which have become much sought after gifts, especially at Christmas time. The kits have revolutionised family tree research and gone are the days of sifting through old documents. But, as Lucy Ash reports, the DNA results are now revealing far more than many had bargained for. How do you react when you find out your mother had a secret affair half a century ago…and the man who raised you isn’t your dad? Produced by Charlotte McDonald. (Image: This chip holds samples of 24 people’s DNA – one in each box. Credit: BBC)