Hi @1pearl, I’m putting together pieces of your ET puzzle. When we first spoke the other day, you mentioned not having the JAK2 mutation and the mystery as to why you have elevated platelets. Reading through your response to another member this morning, I see that you have the CALR mutation. That’s the missing piece of the jigsaw puzzle that fell through the cracks in our discussion.

The CALR mutation is also one of the potential causes for development of a myeloproliferative neoplasm (MPN) such as ET, PV, MF.

MPNs are a type of chronic cancer of the bone marrow that can worsen over time, especially if left untreated. They happen when immature blood stem cells, called blast cells, develop sudden genetic changes that cause them to grow abnormally and out of control. In the case of ET it is platelets. MPNs can also lead to complications like scarring of the bone marrow in MF or myelofibrosis which eventually interfere with production of healthy blood cells causing severe anemia and low numbers of platelets.

Some of the more common genes involved in the mutations known to cause MPNs is Janus kinase 2 (JAK2). However, other gene mutations, called MPL and CALR are also culprits.

A quote from an article in the National Institute of Health/PubMed
“Calreticulin (CALR) mutations have recently been reported in 70–84% of JAK2V617F-negative myeloproliferative neoplasms (MPN), and this detection has become necessary to improve the diagnosis of MPN.”

Link to article: Calreticulin Mutations in Myeloproliferative Neoplasms: Comparison of Three Diagnostic Methods https://pmc.ncbi.nlm.nih.gov/articles/PMC4621046/

Every second, our marrow produces several million blood cells. Daily, that translates into around 200 billion red blood cells, 400 billion platelets, and 10 billion white blood cells. Each cell is a precise copy of each other! If there is even one teeny deviation to a strand of DNA it can alter the course of events. Our immune systems do an amazing job of sniffing out defective cells and eliminating them. However, if the cells elude detection they can proliferate out of control, eventually crowding out the healthy cells. So keeping them under control can be vital to continued good health.

A little reading material… (There are many reputable sources online regarding MPNs or specifically Essential or Primary Thrombocythemia)
https://www.healthline.com/health/cancer/myeloproliferative-disorders
So, for what it’s worth, there’s the missing piece. The CALR mutation. Hopefully this is helpful in clearing up part of your mystery.
Have you considered a 2nd opinion?