Jak 2 exon 12

My rbc and hemoglobin and iron are all high but my mcv hct mch mchc are all. Within range. I tested negative for jak 2 test last year 2022. But because my rbc and hemoglobin are still up my haematology has done a jak 2 exon 12 because they can't under why my bloods are still up. Any information is much appreciated. Anyone ever experience this and got a negative jak 2 exon 12. Thanks

[Aime]

Hi Chese

I am negative to both Xeon and Jak2 but still have too many red blood cells. I was told I didn’t have Polycythaemia vera but idiopathic erythrocytosis (too many red blood cells, cause unknown). I believe it’s also known as Polycythaemia, without the Vera!

I am monitored with blood tests every 3 months if stable and I haven’t had blood taken off for about 18 months. I have, however, had several orthopaedic ops, which may have helped the red blood cell count?

I think and have been told that as long as I’m monitored then I should be fine.

Hope that makes sense, kindest regards Aime

[Hidden in reply to Aime]

Thanks Aime. Can you explain a bit about polycythaemia.

[Aime in reply to Hidden]

As far as I understand, Polycythaemia just means too many red blood cells. Sorry I’m no expert but the best place to get that information is from the website associated with Healthunlocked, MPN Voice. This website is monitored and information is up to date and correct, Dr Google, isn’t as reliable. Hope this helps, kindest regards Aime 😺

[Hidden in reply to Aime]

I hope you don't mind me asking what is your hemoglobin and rbc levels when you tested negative for jak 2 and with the exon 12 test thanks

[Aime in reply to Hidden]

I cannot remember my exact levels when I was first tested for Polycythaemia. Both levels were high and so were my platelets. More information on what is normal/high/low is on MPN Voice website. Kindest regards Aime 😺

[Hidden in reply to Aime]

Hi Aime just wondering if I could ask what symptoms do have for polycythaemia. Thanks

[Aime in reply to Hidden]

hi, symptoms I have are: itchy skin, fatigue, sweats, pain on left side under ribs. I hope this helps you, kindest regards Aime 😺

[Confusingdisease]

have you had a test for the hemochromatosis gene? You said your iron is high, which doesn’t really seem like PV to me. With PV, iron / ferritin are usually on the lower end cause your body is making all the extra red cells.

[Hidden in reply to Confusingdisease]

Negative result hemochromatosis. a family member tested positive for it. Thanks

[hunter5582]

Confusingdisease makes a very good point about another possible explanation for your unusual numbers. Aime does as well. Sometimes the erythrocytosis is idiopathic. A bone marrow biopsy would shed light on your proper diagnosis. Have you had one yet? Note that there are a very small number of people with PV who have the CALR mutation or no known mutation.

There is evidence that some people with PV may have a noncanonical JAK2 mutation. In one study "two JAK2-mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected" pubmed.ncbi.nlm.nih.gov/311...

Many of the tests only check for the known JAK2 mutations, JAK2v617f and JAK2 Exon 12. They are not designed to look for other types of JAK2 mutations. There are genetic tests that do look for a broader range of mutations. labcorp.com/tests/489555/i-...

Something to understand about mutations is that we all have them. On the average, we gain 20 - 24 new mutations in every year of life. These mutations are usually benign. Some mutations are known to be malignant. Some mutations are considered to be Variations of Undetermined Significance (VUS).

Your situation is similar to one in my family, where we have a Familial MPN. I have the JAK2v617f mutation with PV which was originally ET. My daughter has the JAK2v617f mutation with ET that seems to moving towards PV. My son has idiopathic erythrocytosis. He is negative for JAK2v617f. He is going back in for additional more advanced NGS testing soon.

Hopefully you are consulting with a MPN Specialist on your situation. MPNs are rare diseases and your situation seems unusual. mpnforum.com/list-hem./

Wishing you success in figuring out what is going on.

[Hidden in reply to hunter5582]

No bone marrow. Haematology are a bit confused themselves as to what's going on. Got jak2 test done last year 2022 came back negative which doctors said I was very lucky my rbc is up and down like my hemoglobin and iron the last 10 years my doctors said there is no worries. Got bloods done October 23 rbc and hemoglobin were up so my doctors referred me to the Haematology.asking why my doctor referred me for I was as clueless as them but knew it had something to do with rbc and they said if my jak 2 exon 12 came back negative they would sign me off there system and go off live my life.

[hunter5582]

Suggest that you need a proper assessment and diagnosis. If this group of hematologists does not have the skillset to do this, it would be in your best interests to seek services elsewhere. Bear in mind that you can have PV and be negative for both JAK2v617f and JAK2 Exon 12. Making this assessment requires a very specific set of knowledge and skills. Suggest consulting with a MPN Specialist even though what you are experiencing may be something else. This may be something other than a MPN. It may be something relatively minor. It is not, however, something to just ignore without knowing what is going on.

Wishing you all the best.

[Aime in reply to hunter5582]

hi Hunter,

Hope you are well. My counts appear settled now, it’s more orthopaedic issues I have! Had an op on my hip (badly torn tendon) on 8 August last year and now heading for surgery on left foot first at the beginning of March, followed by right foot some time later. I’m not sure if the ops are keeping my counts low or not but I haven’t had a venesection for at least 18 months.

Take care, nice to be back on this forum again, before my osteoarthritis takes priority again. Aime x😻

[hunter5582 in reply to Aime]

Glad to see you back on the forum and that the numbers are looking good. I am also having more issues with the osteoarthritis right now. I need the hyaluronic acid injections into my knees. Medicare covers it but has the process so tangled up in ridiculous red tape that i am having trouble getting it set up. I am currently climbing a tall mountain but will get to the top.

[Aime]

I will keep everything crossed that you get the injections soon. Do you have access to a hydrotherapy pool? I find it really goodfor keeping joints moving and reducing pain. Take care Aime. 🙂