I also wondered this when my Mom was first diagnosed and from what I have read and heard know one really knows for sure. My Mom is convinced that her Dad has PD as well. I get shaking at times (I am 24) but I think this is normal and we may simply be more aware of it. I wish there was an answer for us, but I have found no convincing answers, I too am interested in hearing what others have to say. Rachael [log in to unmask] My father has PD and was wondering if it is hereditary. I notice some shaking somedays (I am 31) and my two sisters also have some shaking. Does anyone have info on this. Colleen Carey [log in to unmask]