Genes involved are unknown. Mechanistically, either trisomy 1q or monosomy 18p that results from the unbalanced translocation may potentially contribute to leukemogenesis. Whole arm chromosome translocations resulting in trisomy of the long arm of chromosome chromosome 1 have been identified with several partner chromosomes including chromosomes 7, 9, 13, 15, 16 and Y in BCR-ABL-negative myeloproliferative neoplasms (MPN). While the underlying mechanisms for these chromosomal alterations are unclear, it is likely that chromosomes with large constitutive heterochromatin bands such as chromosome 1 may be at risk of centromeric instability and be predisposed to centromeric fusion with other chromosomes.
These observations suggest that a gene dosage effect of certain chromosome 1q regions, analogous to numerical aberrations may be involved in disease pathogenesis. Additionally, deletion of 18p may also contribute to clonal proliferation through loss of putative tumor suppressor genes, analogous to numerical aberrations and deletions associated with both chronic and advanced phases of MPN. In support of this contention, deletions on chromosome 18p as a result of der(18)t(9;18)(p13;p11) and der(9;18)(p10;q10) associated with the JAK2 V617F mutation have been described with phenotypes of transitional PV and IMF, suggesting that 18p deletion may be associated with myeloproliferative disorders showing a high propensity to transformation.
While the association of derivative (1;18) with JAK2 V617F still remain elusive, it is possible that that patients having this chromosome abnormality together with the JAK2 V617F mutation may belong to the subgroup of patients with highly proliferative phenotype of MPN which potentially transforms into acute myeloid leukemia.