In 2005, similarity in the major disease groups of MPDs got some explanation when Janus Kinase 2 V617F (JAK2- V617F) which in fact represents a G to T somatic mutation of JAK2 at nucleotide 1849, in exon 14, which eventually end up in the substitution of valine to phenylalanine at codon 617 (Tefferi 2006).
Apparently, it seems that all group members of MPDs contain JAK2-V617F in equal proportion in all patients, persistently; which raises the question of capturing all disorders in the group through a single mutation, how is it possible But this is not the case!
In fact, various diseases of the group carry this mutation in their genetic materials with different proportions in different patients; moreover, these diseases do not constantly carry this mutation as a universal principle. ...
Various researchers have got the evidence to describe that the proportion of the patients with one of the three diseases of MPDs carry JAK2-V617F in different proportions and among these diseases PV is the disease which carries it to the maximum level. According to Tefferi (Tefferi 2006), almost all patients with PV carry the mutation while in the remaining two diseases, ET and IM, about half of the patients each in the two groups carry JAK2-V617F. While Jones et al (Jones 2005) gave could capture lower frequency of the mutation in these diseases, like: 81 percent of the patients with PV could show JAK2-V617F, 43 percent with IM and 41 percent with ET were able to reflect the mutated genetic material.
This non-consistent behaviour of the mutated genetic material demands some further exploration in this area. One possible explanation in the favour of single mutation with multiple diseases still exists and which is related to sensitivity and specificity of the tests capturing the findings, which support JAK2-V617F. There are chances that mutation is present in the disease groups belonging to MPDs but the available tests are not efficient enough to detect that. For this answer we need to wait for the availability of refined testing system.
At the same time it seems obvious that some other mechanisms are also operating in differentiating the progenitor to different diseases. Whether these mechanisms are timed before, after or at the same time as the mutation develops; it is to be answered.
Jamieson et al (Jamieson 2006) found through their study that: in samples of PV patients, the cells with haematopoietic stem cells phenotype produced JAK2-V617F which in