Blood Results Allele Burden Query

[Hocus58]

Hi

I have just received my blood reports from my health authority as requested for my appointment with MPN Specialist.

Can anyone tell me what the below means please.

“Allele specific to detect the JAK 2 variant c.1849G>T p.(Val617Phe) was performed. We estimate that the level of detection for the tests performed is >5%”

Should it not give a specific percentage ?

Thanks in advance

[hunter5582]

There are two types of JAK2 genetic tests, quantitative (%) and qualitative (Yes/No). All genetic tests have a level of sensitivity below which the results will be considered inconclusive or negative.

[Hocus58 in reply to hunter5582]

Thank you Hunter, excuse my ignorance, so does the sentence above not really tell me anything of note.

[hunter5582 in reply to Hocus58]

It appears to say that the test is positive for JAK2 at a level above 5% without giving the specific allele burden. I would take this to be a qualitative test.

[Hocus58 in reply to hunter5582]

Thank you, every day is a school day 🙂

[hunter5582 in reply to Hocus58]

I just reread the quote. I think EPguy is right. It should give you a more clear yes no answer.

[EPguy]

That would be a yes/no as Hunter says.

But as literally worded they told you only what they looked for and a limit of what they can find, while not saying what they found. Usually you should see info within this text like:

"Allele specific to detect the JAK 2 variant c.1849G>T p.(Val617Phe) was performed. (Jak 2 V617F was, or wasn't, detected) We estimate that the level of detection for the tests performed is >5%”

If it was "not detected" you still don't have a great answer since less than 5% is still relevant to MPN. Modern quantitative tests can go to 0.1%. If it "was detected" it could be between 5 and 80+ %. This is worth knowing.

With this vague result, they likely did not look for any other mutations beyond Jak2. (nextGen sequencing) This is considered by many Drs to be useful info to guide future treatments and progress.

[Hocus58 in reply to EPguy]

Hi EPguy thanks for your input, looking further at the letter the conclusion, which is in a different area 😬 states -

“JAK2 variant c.1849G>T p.(Val617Phe) detected”

Then in a completely different part the text on the original post.

Very confusing for someone just recently diagnosed I’m afraid.

Thanks for your support.

[EPguy in reply to Hocus58]

I expected there had to be more, so it is the qualitative test as Hunter describes. So you now know it's between 5 and 80+%.

Your Dr really should help you understand all of this. Dr should also get you the quantitative test and NexGen results as references future therapies. For example if you may choose interferon therapy (INF) at some point, INF can reduce the Jak2 %, (allele) but you need an actual starting value to track that.

The option to possibly reduce allele is only recently well accepted and some Drs are still not fully with this yet.

[Hocus58 in reply to EPguy]

Thank you, I have a f2f appointment with haematology consultant end August and one with an MPN Specialist in October. I will be bringing this and more up with them then.

Thanks for the support

[EPguy in reply to Hocus58]

You may hear from Dr that there is no proven benefit to reducing allele, this is a sort of stock answer. It's broadly correct; it takes decades to get clear answers with MPN. But the evidence over past decades points to benefit, we've had many posts on it. My take is I'd rather reduce it and find out it didn't matter than not try and find out it would have mattered.

[jointpain in reply to EPguy]

My wife's hematologist has given the stock answer of not worth checking the allele burden again of the Jake she has. It was checked in France when she had her Splenectomy after it ruptured and was found to be over 75% that was four years ago. I have no idea how quickly it can or does rise, but it is a worry when so high. Luckily she is so fit when not bleeding from GI. Hopefully over 5% isn't very high at all.