My father has total bone loss in one wrist and his thumb bone in one hand. It is spreading to his other wrist currently. It starts as small pencil eraser sized holes that eventually eat the entire bone away. We're told it is genetic. It is very painful until the bone is completely gone and then he said it no longer hurts. We've also been told there is no treatment or cure. What is the name of this disease and what can be done to make sure it isn't passed on to other family members? Thank you.