Acquired Trisomy 12 and Absent Y Chromosome in a Patient with Acute Undifferentiated Leukaemia

Abstract

A 60-year-old man developed pancytopenia and then acute leukaemia. The neoplastic cells in marrow were undifferentiated by electron microscopy and by immunological and cytochemical markers. The only other cells present in marrow were lymphocytes, plasma cells, macrophages and non-haematopoietic elements. Prior to chemotherapy, cytogenetic analysis of marrow cells showed two karyotypically distinct cell populations, one with 45,X,-Y and the other with a 46,X,-Y,+12 karyotype. All marrow cells stimulated by protein-A from staphylococcus aureus were 46,X, -Y, + 12. Phytohaemagglutinin-stimulated cells were normal, 46,XY. These findings suggest strongly that most of the undifferentiated leukaemic cells were missing the Y chromosome. A subpopulation of these leukaemic cells also had trisomy 12. These observations and previously published findings suggest that trisomy 12 occurs non-randomly in haematological disorders, and in particular, may be associated with Blymphoid malignancy.

Cytogenetic abnormalities in acute leukaemia of ambiguous lineage: an overview

“…Trisomy 12 has been observed in AUL as a recurrent chromosomal aberration (Najfeld et al , ; Cuneo et al , ). In one patient, a 60‐year‐old male, trisomy 12 was detected as the sole change.…”

“…Moreover, trisomy 12q was found in a complex karyotype with monosomy 17 and polysomy 21q, in a 60‐year‐old female with AUL. The duration of CR was 10 months and OS was 16 months (Najfeld et al , ; Cuneo et al , ). Trisomy 12 is among the most frequent aberration in CLL with an intermediate prognosis (Rodríguez‐Vicente et al , ).…”