JAK2 results

Hi everyone, I was diagnosed last Thursday with Polycythemia Vera and I am so confused. The Haematologist rang me and told me the results but on my medical records at the Doctors it is described a JAK2 Negative Polycythemia Vera and even though it says ‘negative’ I still have the condition. The Haematologist - although a very nice man - was very laid back about it all and he could talk the legs off an Oil Rig and I did not have a chance to ask him much. I really didn’t have a clue what polycythemia Vera was till I googled it and I was so shocked. I have not heard a thing from my Doctors and I already have NARliver disease, an enlarged Spleen and Gallbladder, Polymyalgia, Fibromyalgia, Thromobcytopenia, Diabetes and a million other ailments. I have no names for a Haematological Nurse or the Haematologists Secretary and I can’t see my Doctor till 4th October, I would be very grateful if anyone able to clarify what JAK2 - ‘NEGATIVE’ is? I have all the symptoms of polycythemia Vera (unfortunately) but am at a bit of a loss. Any information would be gratefully received.


Hi @kitty001 a great big welcome you are now part of our forum family.
You have had an overload of information to take in since last Thursday,.
I was in shock for ages after my diagnosis and I felt in a bubble with the world just going on around me.
I am certainly not a medical person but what I have learnt to do is to write down all my questions and not leave my appointment till they are all answered.
I also had a list of all my other conditions and medications because they all go together to make me a very special unique person as you are too.
Also ask for a specialist nurse or Haematology secretary contact details.
Perhaps be pleasantly assertive.
If you would like to talk to someone the Blood Cancer UK support line is there for you on 0808 2080 888
I think being a bit of a loss sounds very natural to me and the main thing is to really look after and be very kind to yourself.
Please do keep posting how you are doing.


Hi @kitty001

Firstly welcome to the forum and thank you for posting.

I too have Polycythaemia vera (PV) and not at all surprised at the lax approach from your Haematologist regarding the condition.

To answer your main question it’s very common to be jak2 positive with Polycythaemia vera (PV) (around 95% are positive) and though it’s not common there are plenty people who are negative too.

That being said the jak2 gene isn’t the main factor of Polycythaemia vera (PV). Where it comes into play is the treatments where one maybe better than others.

Often the jak2 is diagnosed through a bone marrow sample but this isn’t essential. I didn’t have to have a bone marrow biopsy for them to diagnose me as positive. I can only assume it was via blood test.

Yes google can very scary and I believe bcuk are very close to releasing a booklet introducing people to Polycythaemia vera (PV) and it looks fantastic.

Like with many conditions, there will be people who have been absolutely fine with Polycythaemia vera (PV) and other cases where people have/are struggling. It’s best to remember you are you and everyone’s story/journeys are different but can be similar and relatable.

Speaking with 3 years diagnosis and still learning it is a very slow build but it’s really important to build a relationship with your medical team and report or keep a diary of how your feeling and discuss these at each appointment.

Lots of people including myself during my early days have posted a lot about Polycythaemia vera (PV) which is really useful and along with the amazing people on this forum having Polycythaemia vera (PV) is not something you go through alone.

Along with your other medical issues don’t get too anxious if it seems quiet from your med team but do remind them of your other conditions as sometimes though it’s all medical there can purely be focussed on their speciality and see that as a priority or be hesitant to start you on anything.

I’m happy to discuss any questions you have but the support line and the nurses here are brilliant!

Look forward to hearing more from you


Hello @kitty001 and welcome to this forum. I am glad you have found us so soon after your diagnosis but I am so sorry about your experience so far. I have a different blood cancer to you, namely myelofibrosis so I can only speak from a fellow patient’s point of view. Polycythaemia Vera is in the same category as myelofibrosis and they are known as Myeloproliferative neoplasms (MPN)’s. There are various genes involved in these conditions that can become faulty. This is not something we are born with but the genes can become faulty. One of the genes involved is the JAK2 gene and it seems you have tested negative for this faulty gene. There are other genes apart from JAK2 that can be tested. I am also JAK2 negative. Sometimes different treatments can be used which target particular genes and that is why testing is done at the point of diagnosis. I hope I haven’t overwhelmed you with too much information. I would encourage you as @Erica has said to ask about a haematology nurse specialist who you could be assigned to. I wish you well. Willow x


You are so kind thank you for replying. I was so confused with the positive/negative, it seems of you’re positive you have it and if you’re negative you have it -my brain hurts :face_with_head_bandage:. But it’s good to have some sort of explanation because I’m not pleased at being left floundering.


Thank you very much for replying, up until I found this forum I was getting frantic but you all seem very helpful. I do have lots of other questions particularly regarding medication which I will post tomorrow. Thank you very much.


Thank you so much for replying. Until I found this forum I was going out of my mind and Google can be a bit overwhelming. I have a million questions I need to ask as my doctor appointment is far off yet. But I have started to write things down as you suggested and oddly it does help - it gives me a bit of perspective. Once again thank you and look out for my questions although I will try not to overwhelm people.


Hey there @kitty001, another fellow Polycythaemia vera (PV) survivor here. Yep, now that you’ve been diagnosed you’re a survivor of blood cancer. It’s still bonkers to me. I’m really sorry to read that you’ve been diagnosed too, but it’s great that you’ve found this forum full of lovely supportive folks who know what you’re going through.

My Polycythaemia vera (PV) was found after my doctor did a blood test to check for the JAK2 gene mutation when I told her that a close relative had tested positive for the mutation. Like @Rammie18 and @Willow have noted, we can be diagnosed with these Myeloproliferative neoplasms (MPN) blood disorders without being tested for JAK2 or even having that specific mutation. Polycythaemia vera (PV) is the blood disorder that you’ll be tending to and learning all about and living with.

Please keep sharing how it’s going for you at this early stage after diagnosis and maybe keep a journal of changes you note in your moods and energy levels and other stuff. It’ll be helpful for reflecting on and noticing patterns in how you feel over time.

The proliferation aspect of our MPNs means we can get fatigued by the process of our bodies overproducing blood cells, let alone fatigued by any medical treatments you might have. It sounds like you’re already juggling some ailments so please look after yourself and eat and rest well.

Shock is exactly how I felt after diagnosis too, plus some sort of grief and all its attendant stages like anger (still so angry at this!). For me the shock has faded a little as treatment carried on, so I hope it decreases for you as well, @kitty001. We’re here to answer any questions we can.