So glad the HU worked fast for you at that low dose! Re the genetic tests, JAK2 patients have higher incidence of clots, which puts them in a higher risk category, especially patients over 60.

Other mutations pop up with the so called "driver" mutations of MPNs (which are JAK2, CALR, and MPL). Researchers really don't know what they mean, if anything. As far as I know, they are collecting statistical data and following patients with these other mutations to see if they are correlated to progression or increased complications. You might tell your hemo that you would like to participate in a data collection effort if that appeals to you. Mine sends my info in. If your doc participates, s/he might get updates on significant developments quicker.

I also started with platelets over one million at age 39. Now I'm 69. I'm also JAK2 positive. After 30 years, I often hear from new hematologists (I've gone through a lot!) that I likely know more about living with the disease than they do, since they don't encounter it very often, especially for someone like me who's had it for 30 years. So, if it's a good doc, generally he/she looks at what I've done to treat it, the success I've had, and tell me to carry on and check in every 6 months. If HU is working at that low of a dose for you, that's great. I'd say that as long as HU is working well for you, try to minimize your stress and not worry too much. No one seems to really have answers to the "why" questions, and you may drive yourself crazy in your determination to figure it out. So I just decided to live comfortably with gray areas in my life!