I believe it can be tested from a blood draw or from bone marrow. I’m going to be interested in learning the results.

Actually it shows on a blood test. Mine is 11% which is not too bad. Interferon should bring it down. I think it measure the activity of the jak2

I asked to have it tested after hearing about it and my MPN Specialist is now tracking this every two years, as another marker. In Spring 2023 I was at a JAK2 VAF of 16% and this Spring 2025 I was at 20%.

Hi MH, I am sorry to hear you feel you are progressing to MF. I had my allele burden checked at diagnosis (2019) and then a few additional times at my request. Many physicians do not routinely check, it seems. I have been taking interferon for years and wanted to know if the AB was impacted (it has steadily decreased). I think it is good to have this information, especially if you feel the disease is changing. Good luck!

Spoke with my Hematologist/Oncologist today. He said that while a higher JAK2 allele burden (mine is 83.98%) correlates with a more aggressive disease, as long as blood counts remain stable and I am not having symptoms it is not something to treat. And I am fortunate not to have symptoms. JAK2 inhibitors, which I am not on, have their own side effects and contraindications, he would make medication changes if warranted but not at this time. It is possible I am moving towards myelofibrosis, which would have to be confirmed by a BMB, but he is not seeing that as warranted at this time. I see him again in August for labs and an office visit.

And so, he confirms what I have read about higher allele burdens, but I’m not at another transformation just yet. It may be on the horizon, but that’s how we live with these, right?

Life with an MPN.