ET Calr type 1 or 2 ?

[Cat_lady52]

How do you know if you are ET Calr type 1 or 2 and does it make any difference?I was just told i had the Calr mutation.

Thanks in advance and have a good weekend 😊

[EPguy]

Your Dr or lab would need to look for it and report to you. There have been some post on it. Note they now call it "type-like", since they have found more subtleties in this area.

healthunlocked.com/mpnvoice...

As reported below, type 1 is more common in PMF while type 2 is more so in ET. So if your Dx is ET, type 2 is more likely, but these are only averages, not predictions of your actual result.

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

"Within ET, type 2–like CALR patients have higher platelet counts" So if your PLT is higher it also suggest type 2.

There are various implication with PMF, but if you have confirmed ET that is probably not not directly applicable.

[Cat_lady52 in reply to EPguy]

Thank you, that makes more sense. I'll ask doc if they know or can test.

[socrates_8]

Hey there Cat_lady...

As mentioned by EP Guy, there are many different Types of CALR, over 50+, and there are likely just as many variations between all of them too...

I am Post ET/MF CALR Type2. My Platelet regime "untreated" sees them at over the 1M+ marker, & possibly in danger of having yet another Transient Ischemic Attack, (TIA - minor brain stroke). I've already had 3/4 of those...

Type 2, usually suggests less Thrombotic events, (according to much of the literature). However, my experience is contrary to those findings thus far. My Platelets usually range from 700s - 1M+

If you have definitely been Dx as CALR, then that requires a special Test to determine that is so, & those results would most likely suggest what TYPE you are. Over 80% of CALR Types usually fall into the Type 1 Or 2 category. Type 1 can be more benign than Type 2. However, saying such things are a generalisation only, in my view...

Hope this helps a tad...

Best wishes, stay happy, safe & well...

Steve

[Wyebird in reply to socrates_8]

thank you I didn’t know there were about 50 Calr types

[Cat_lady52]

Thank you, I'm most likely type 2 , but will ask Dr to confirm.

[socrates_8]

The REPORT on the Test, that determines your "DRIVER" mutation, will also elucidate which Type I am certain... Unless it's one of those weird Variations that take place due to diverse body chemistry, in my view...

Best wihses

Steve

(Sydney)

Steve

[Cat_lady52 in reply to socrates_8]

Thank you, you'd think they'd give me all the info, without me having to ask, I've only been diagnosed for less than 4 months, so still learning about ET and what to ask. This forum and MPN voice are wonderful and informative and people are so helpful. Thank you so much. 😸

[dbus1417]

just wanted to add that there are several promising CALR specific treatments on the horizon. There is currently an antibody that targets mutant CALR cells in clinical trials that leaves wild type (normal) cells alone. Fingers crossed the trials are successful. CALR mutant here 🤙🏽 have a good day and hang in there