Cytogenetics: none specific, reported abnormalities include trisomy 8, t(10;11)(p14q21), t(7;12)(q11;p11).¹  Cases with t(8;9)(p22;p24);PCM1-JAK2 likely will fall into this category.⁴⁴  Molecular genetics: reportedly, JAK2 V617F in < 5%.^28,45