Jason I agree toxins are a reasonable area of research. I do think that you are writing off (or at least minimizing) the role of genetics however a little too quickly. Traits with incomplete penetrance as well as recessive traits and polygenetic traits are well known in medicine. With these it is entirely possible to have no diagnosed disease in a long pedigree.. It is my guess (speculation) that some genetic relationship will be found probably related to environmental factors. There is going to be some research started soon looking for contributing genes and when I know more about it I will let you all know. Also, in addition to toxins such as pesticides there are a whole group of other environmental factors- infections, in utero factors, diet, exercise, climate, emotional , stressors, medications, sun exposure, sleep, as well as aliens stealing our subsatntia nigra because it is the unit of currency on Rigel. I do think that toxins are a good bet but all areas must be but it is only one of many possibilities. My plea is for critical thinking- not against intuitive speculation if it is followed up with close examination. Keep speculating and thinking- but don't write off options prematurely. I likely will continue to take the role of skeptic here on the list. But I really hope you come up with something that is irrefutible. We do owe that to our children. Good luck and keep speculating, Your friendly skeptic, Charlie **************************************************************************** ************************************* Charles T. Meyer Madison, WI [log in to unmask] **************************************************************************** ************************************