Mixed Phenotype Acute Leukemia with t(12;17)(p13;q21)/TAF15-ZNF384 and Other Chromosome Abnormalities

Cytogenet Genome Res. 2016;149(3):165-170. doi: 10.1159/000448447. Epub 2016 Sep 9.

Abstract

The t(12;17)(p13;q11∼21) translocation is a very rare but recurrent cytogenetic aberration observed predominantly in early pre-B acute lymphoblastic leukemia (ALL) with CD19+CD10-CD33+ phenotype. This translocation was shown to form a fusion gene between TAF15 at 17q12 and ZNF384 at 12p13. On the other hand, der(1;18)(q10;q10) has been detected as a rare unbalanced whole-arm translocation leading to trisomy 1q in myeloid malignancies. We describe here the first case of mixed phenotype acute leukemia (MPAL) with a t(12;17)(p13;q21)/TAF15-ZNF384, which also had der(1;18)(q10;q10) as an additional abnormality. A 74-year-old woman was diagnosed with MPAL, B/myeloid, because bone marrow blasts were positive for myeloperoxidase, CD19, and CD22. Chromosome analysis showed 46,XX, +1,der(1;18)(q10;q10),t(2;16)(q13;q13),t(12;17)(p13;q21). Expression of the TAF15-ZNF384 fusion transcript was confirmed: TAF15 exon 6 was fused in-frame to ZNF384 exon 3. This type of fusion gene has been reported in 1 acute myeloid leukemia case and 3 ALL cases. Thus, at present, it is difficult to find a specific association between the structure of the TAF15-ZNF384 fusion gene and the leukemia phenotype. The TAF15-ZNF384 fusion may occur in early common progenitor cells that could differentiate into both the myeloid and lymphoid lineages. Furthermore, der(1;18)(q10;q10) might play some role in the appearance of an additional myeloid phenotype.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Base Sequence
  • Child
  • Child, Preschool
  • Chromosome Aberrations*
  • Chromosome Banding
  • Chromosomes, Human, Pair 12 / genetics*
  • Chromosomes, Human, Pair 17 / genetics*
  • Exons / genetics
  • Female
  • Humans
  • Karyotype
  • Leukemia, Biphenotypic, Acute / genetics*
  • Male
  • Oncogene Proteins, Fusion / genetics
  • Phenotype
  • Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • TATA-Binding Protein Associated Factors / genetics*
  • Trans-Activators / genetics*
  • Translocation, Genetic / genetics*
  • Trisomy / genetics
  • Young Adult

Substances

  • Oncogene Proteins, Fusion
  • TAF15 protein, human
  • TATA-Binding Protein Associated Factors
  • Trans-Activators
  • ZNF384 protein, human