**5.4 3q26 abnormalities**

The IPSS-R considers the 3q26 alterations: inv.(3)(q21q26), and t(3;3)(q21;q26) as pejorative abnormalities, they rearrange the MECOM (MDS1/EVI1) locus with complex oncogenic roles and may be accompanied by thrombocytosis. Numerous other partners of EVI1 are reported as PRDM16 in t(1;3)(p36;q21) and RUNX1 in t(3;21)(q26;q22).
