DNA test positive for JAK2V617F does this mean I definitely have a MPN?

[happy007]

This result came at random I have zero symptoms so can I have this ene and it mean nothing? Or does it mean I definitely have a MPN? the dna test result just said 99.5% higher risk of MPN. I do't know a thing about this topic. Do I need to go to dr?

[EPguy]

Did they give you a VAF? (variant allele frequency) This is the % of your Jak2 that is mutated. It can be anywhere from less that 1% up to near 100%. There are other names for this measurement too.

You get this info from the "quantitative" test, how much is mutated. If you had the "qualitative" test it shows only whether any mutation was found.

It's not unusual to have MPN without symptoms. Many find out only from a test for other reasons. I am not so fortunate, I have plenty of symptoms.

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You can also have Jak2 mutation (it's called Jak2 v617f) and not officially have MPN. This can be "CHIP" as discussed here.

mpn-hub.com/medical-informa...

"Clonal hematopoiesis of indeterminate potential (CHIP) is a state in which somatic mutations are found in the cells of the blood or bone marrow but does not meet the World Health Organization (WHO) criteria for hematologic malignancies."

Having CHIP does usually increase risk of MPN developing at some point.

[happy007 in reply to EPguy]

Honestly, I have no clue. I did an online dna test one said I had 99.5% higher chance so I ran it through Promethease in hopes of better information but that didnt help it said I have rs77375493(G;G) which the description says "rs77375493, also known as V617F or Val617Phe, is a variant considered to generally be acquired (i.e. somatic) in the Janus kinase 2 JAK2 gene. " Here are the pictures from the report in case you know what they mean.

dna

[EPguy in reply to happy007]

Understand, you got a "curiosity" type test rather than Dr ordered.

This report discusses in (too much) detail the report in your image.

"As reviewed, the JAK2 haplotypeGGCC_46/1 is a germline inherited condition which confers a predisposition and an increased risk of developing MPN, preferentially but not exclusively in association with the JAK2 V617F mutation"

ncbi.nlm.nih.gov/pmc/articl...

By this your result increases odds of acquiring the v617f mutation. but does not say you have it. But something is at 45% frequency. This is the way v617F VAF is described for us but does not mean it is the same thing here.

There is a "more info" tab in the image, is there any useful info there?

We don't usually see our genetic tests in the form you have here.

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But the Promethease report is clear. It's first time I've seen another name for v617F: rs77375493(G;G). The -F is a modern spelling for -Phe, but describes the same mutation of Jak2.

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Have you had any conventional blood tests recently? MPNs usually will show certain results, and in fact before ~2005 an old fashioned blood test was a main way to suspect MPN.

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Bottom line is you should make Dr appt and discuss all this and blood test results. Ultimately you'll likely see a hematologist (or even better, an MPN specialist) who can order a proper genetic test for you and interpret it and the blood tests.

[rocket95001 in reply to happy007]

Have your Dr run another test to confirm JAK2 gene and check for levels of Hemoglobin (HGB) and Hematocrit (HCT). If JAK2 gene comes back positive you have PV, also if HGB is higher than 15.5 or HCT is higher than 50% then you should be put on Xarelto and have phlebotomy when numbers are above those limits. Getting on Xarelto is critical. I had my 4 pulmonary embolism 2 weeks after a phlebotomy. That meant I should have also been on Xarelto all along. Don't wait until you end up on the hospital...

[hunter5582]

It is a bit unusual for a doctor to order a JAK2 analysis in the absence of symptoms. Were there some findings (e.g., elevated platelets) even though you do not have any other symptoms? Many people with MPNs are initially diagnosed by a routine CBC even though they feel fine. that happened to me about 30 years ago.

As EPguy explained, some people do have the JAK2 mutation without manifesting the disease, Clonal hematopoiesis of indeterminate potential (CHIP). In addition, it appears that many people with the JAK2 mutation acquire the mutation in early childhood but it takes decades for the disease to manifest. hematology.org/newsroom/pre...

None of us can answer the question about whether you have a MPN. It would be advisable to consult with a MPN Specialist at this point. Note that regular hematologists rarely handle MPNs due to how rare they are. It is best to consult with a MPN-expert doc. Here are two lists.

Worldwide mpnforum.com/list-hem./

USA pvreporter.com/mpn-speciali...

All the best moving forward.