This question was originally posted on Quora.com and was answered by Rachel Anderson, Scientist, battle-pedant, feminist, reluctantly political This isn’t about my genetic test - it was my baby brother who got a 23 And Me test as a gift. But it kind of answered a family mystery. My paternal grandmother’s father was a ‘blow-in’. In the 1860s he appeared in the locale, Ballyshannon, looking for work. No one knew him, he had no references or affadavits, so he didn’t have much luck. Eventually, a widow with young daughters and a farm larger than she could manage hired him as a farm labourer. He worked hard. He gained respect, for that at least. He never made any real friends, and never volunteered any information about himself - and, on the rare occasions that anyone was rude enough to ask, he somehow wriggled out of answering. He didn’t drink, didn’t smoke, had no vices. He attended church with the widow and her family, respectfully taking a seat at the back, stood and kneeled at the right times, but didn’t sing or pray openly. In the mid-1870s, the widow offered him the farm on her death and his choice of her daughters as wife. They duly wed, and had a large family, of whom my grandmother was the second-youngest. When he died, no one knew anything more about him than they had when he first blew into town. This might not seem all that interesting a story to many people today, but it was pretty big at the time. His appearance was not too far removed from the Famine, which left many dispossessed and travelling the country for work. He could have been a Traveller, an Irish gypsy. Rebels against the Crown also wandered through communitites, and his performance in church didn’t allay any fears on this score. And it’s frankly bizarre that a man could live near, and trade in a major market town without somebody from his past seeing and recognising him. Any hoo. Brother, genetic test, etc.: we’re apparently related to a wealthy Scottish family who still own estates in Ireland, with a castle and everything. This family has the surname my great-grandfather used. Brother is still trying to figure out how gg-paw fits into this family: none of them went missing. It’s possible he was illegitimate - but if so, who was he, really? And why did he use the name? And it was also answered by Kay Aull, PhD Bioinformatics We figured out why the men of my dad’s family didn’t live past 60. Growing up, I heard occasional references to the “family curse”. I thought it was superstition, mostly, but I knew about it. And it’s quite possibly the reason I went to MIT. My dad knew that was my top choice - I knew it would involve him writing a six-figure check, when I could’ve easily gotten a full scholarship to some very good schools. So I sat him down and asked if he was okay with that, and he told me to go to MIT. And I did. He was about to turn 60, and sure enough, he was developing mysterious health problems. He didn’t say it, but I don’t think he was planning to use his retirement savings. The family curse was coming for him. Then his doctors figured out what was wrong with him, and confirmed it with a then-recently released genetic test. Hemochromatosis. Entirely treatable, by the way. He’s fine. I’m a carrier, thanks Dad. My ancestry, however, was exactly what the family history predicted. I’m an American Euro-mutt, about half German and half English. Apparently a bit of Scandinavian snuck in there during the 1700s, though...shocking, I know. Source