Dupuytren's Disease is a genetically inheritable condition that causes the fibrous connective tissue in a person's hand to thicken, causing the fingers to curl permanently inward. Some people get surgery to correct it. In severe cases, the hand becomes a withered, useless claw, and some patients opt to have their hand amputated.
I have a mild case in my right hand. It appeared a couple of years ago and is slowly getting worse. It's a little painful in the morning when I wake up until I gently stretch my fingers.
Today I read an article in Discovery citing a study that says Neanderthal DNA is "partly to blame" for the condition:
Scientists have identified a long list of risk factors for Dupuytren's: Men are more likely to develop it than women, and the condition affects not just people of northern European descent but also Scandinavians. Certain medical conditions, including diabetes and seizure disorders, increase one's risk as well, as does old age. The study drew on genomes from 7,871 people who had Dupuytren's and found 61 genes related to the disease, including three that had come from the Neanderthals. Of those, two stood out as the second and third most important for predicting Dupuytren's.