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JAK2 V617F mutation

Genetic tests · also printed as JAK2, JAK2 mutation, JAK2 V617F, JAK-2, JAK2 exon 12

Typical UK adult rangeExpected result: Not detected

Not detected is the expected result.

What this test measures

The JAK2 V617F test looks for an acquired change in bone marrow cells that drives several conditions where too many red cells, platelets or white cells are made.

Why doctors request it

Requested when a blood count shows persistently high red cells or platelets without an obvious cause.

What commonly pushes it up

One of the myeloproliferative conditions (polycythaemia vera, essential thrombocythaemia, myelofibrosis)

What commonly pushes it down

A negative result is the usual finding

Everyday reasons for a value outside the range

A low-level positive is occasionally found with a normal blood count and is followed rather than acted on

About the sample

No fasting needed.

Written by a UK consultant physician. Typical UK adult reference ranges; your laboratory's own printed range takes precedence.

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This is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.