T(4;22)(q12;q11.2) involving presumptive platelet-derived growth factor receptor A and break cluster region in a patient with mixed phenotype acute leukemia

Huan You Wang, John A. Thorson, H. Elizabeth Broome, Hooman Rashidi, Peter T. Curtin, Marie L. Dell'Aquila

Research output: Contribution to journalArticle

4 Scopus citations


The patient is a 45-year-old woman with a history of breast cancer who had been treated 1 year ago with radiation and chemotherapy. Flow cytometric analysis of bone marrow aspirate revealed 81% blasts positive for CD4, CD11c (partial), CD13, CD19 (partial), cytoplasmic CD22, CD34, CD36, CD45, cytoplasmic CD79a, CD117 (partial), HLA-DR, and terminal deoxynucleotide transferase, consistent with a mixed phenotype acute leukemia (B/myeloid lineage). Conventional karyotypic analysis revealed a t(4;22)(q12;q11.2) in 12 of 13 cells analyzed. Fluorescence in situ hybridization analysis using a dual-color, dual-fusion break cluster region/ABL probe set showed no break cluster region/ABL translocation but an extra break cluster region signal in 85% (170/200) of cells, consistent with a translocation involving the break cluster region gene at 22q11.2. A FIP1L1/CHIC2/platelet-derived growth factor receptor α deletion/fusion probe showed signal separation in 96.5% (193/200) of interphase nuclei. Reverse transcriptase-polymerase chain reaction using sense break cluster region primers and an antisense platelet-derived growth factor receptor α primer resulted in a product of approximately 590 base pairs, consistent with the presence of a break cluster region/platelet-derived growth factor receptor α fusion gene. Because of the presumptive platelet-derived growth factor receptor α translocation and its sensitivity to tyrosine-kinase inhibitor, the patient was treated with imatinib mesylate, cytarabine, and idarubicin as induction and maintenance therapy; and she has remained free of disease for 5 months since the initial diagnosis.

Original languageEnglish (US)
Pages (from-to)2029-2036
Number of pages8
JournalHuman Pathology
Issue number12
StatePublished - Dec 1 2011



  • Break cluster region
  • Mixed phenotype acute leukemia
  • Platelet-derived growth factor receptor α
  • t(4;22)(q12;q11.2)

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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