I was told by my old doctor that it was his hypothesis that ET was related to people who live in prolonged, high stress lifestyles. He said that when people are stressed their platelet count naturally raises. When your body is constantly stressed and therefore increasing platelet production over a length of time the cells mutate, resulting in ET.
It would be interesting if there is any research on this. I would love to know how I got this and if it could have been prevented.