We welcome this interesting case report. It is the first description of a JAK2 mutation in Down syndrome–acute megakaryocytic leukemia (DS-AMKL). It also confirms that some cases of DS-AMKL will harbor a JAK3 mutation.
However, it is still the case that, taking all the published literature to date, the frequency of JAK2 and JAK3 mutations in DS transient myeloproliferative disorder (TMD) and AMKL is low and that these events are not obligate mutations for leukaemogenesis in all cases of DS malignancies, in contrast to the almost invariant finding of a GATA1 mutation. Given this, we are still of the opinion that there may be several different (epi)genetic events that could be permissive for the progression of TMD to DS-AMKL and that these could individually occur at low frequency.
Authorship
Conflict-of-interest disclosure: The authors declare no competing financial interests.
Correspondence: Paresh Vyas, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom; e-mail: paresh.vyas@imm.ox.ac.uk.
