Actions

MPL

From www.haematologyetc.co.uk


Gene affected:
MPL originally described as the oncogene of 'myeloproliferative leukemia virus' (MPLV). Now recognised to encode the thrombopoietin receptor


Clinical significance
MPL mutations are seen in several MPNs where the risk of VTE and AML transformation are higher that those with CALR mutations (Type 1). Certain prognostic scores take this mutation into account.



Function of gene

MPL encodes the thrombopoietin receptor protein. The activated thrombopoietin receptor stimulates the JAK/STAT pathway, driving progenitor expansion and early stages of megakaryocyte differentiation as well as haematopoietic stem cell survival and proliferation.


NGS panel gene coverage

The panel recognises exon 10 of MPL


Occurrence:


MPN (2-3% ET, 3-5% PMF)
MPL mutations are associated with increased VTE and transformation to AML as compared to Type 1 CALR mutations
MDS/MPD-RARS-t. (<5%)
Prognostic implications are unclear

Germline mutations are associated with Congenital Amegakaryocytic Thrombocytopenia (CAMT) which can evolve into aplastic anaemia or AML.




Associated genetic features:

Mutually exclusive with JAK2 and CALR mutations.



Links

GeneWiki link:
Gene Wiki entry for MPL
References
Review of MPL in PT1 cohort