While it's not hereditary in the sense of Mendelian genetics, it probably does run in families, and there probably is a genetic predisposition. It goes back to the age related question. Why are there some fifty year olds who have arthritis and others who don't? Well, there has to be something in their genetic makeup that gave them a predisposition to develop this at an early age. Right now, I don't think we have a clear handle on that, but there's research being done at centers all over the world that are trying to pinpoint this in the hope that if we can develop a way to assess for a genetic marker, we might be able to pick those patients out earlier and maybe either counsel them on dos and don'ts as they get older or maybe, and this would be really super cool, be able to manipulate it with medication of some sort.
