A rare case of complex variant translocation of t(9;22;16)(q34;q11.2;q24) in a newly diagnosed patient with chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm associated with the dysregulated production of myeloid cells. The Philadelphia chromosome (Ph), t(9;22)(q34;q11), is a hallmark of the disease and found in 90-95% of diagnosed CML patients. The balanced, reciprocal translocation places the genes and , next to each other, resulting in an increase of kinase activity. Additional cases involve complex variants, including translocation events involving an additional chromosome with the creation of the Ph chromosome. A rare three-way Ph chromosome complex variant, t(9;22;16)(q34;q11.2;q24), was identified in a 40-year-old female who presented with visual changes and leukocytosis. Cytogenetic analysis by G-banding revealed the presence of a three-way translocation involving the long arms of chromosomes 9, 22, and 16. Fluorescence in situ hybridization with a dual-color fusion probe confirmed the presence of the fusion.