Trisomy 11 and a complex t(11;11;22) in a patient with acute myelomonocytic leukemia (AML-M4) following myelodysplasia (MDS): a cytogenetic study of a mechanism of leukemogenesis.
We describe a 73-year-old man diagnosed with acute myelomonocytic leukemia (AML-M4) following myelodysplasia with trisomy 11 and with a t(11;11;22). This is the first case with both abnormalities present in the same cells and with the t(11;11;22) involving a chromosome 11 already duplicated at 11q23. This band contains the MLL gene that undergoes partial tandem duplication in patients with +11, which is "promiscuous," being translocated with a large number of genetic partners. Our patient had a complex karyotype that was completely defined by in situ hybridization. This technique demonstrated that the t(11;11;22) derivative with a duplication of band 11q23 carried from three to four copies of MLL. Two copies of the gene were close to each other and centromeric to the break-point region. Therefore, a partial tandem duplication of the MLL gene might have happened before the occurrence of t(11;11;22). Considering the associated chromosome defects, the monosomy for the long arm of chromosome 7, due to an unbalanced translocation t(7;17), further underlines the possibility that a partial tandem duplication of the MLL gene might have taken place.
Bernasconi
P
P
Istituto di Ematologia, Università di Pavia, Italy.
Cavigliano
P M
PM
Boni
M
M
Malcovati
L
L
Astori
C
C
Castagnola
C
C
Pagnucco
G
G
Vanelli
L
L
Calatroni
S
S
Caresana
M
M
Lazzarino
M
M
Bernasconi
C
C
D000368:Aged; D002880:Chromosomes, Human, Pair 11; D002892:Chromosomes, Human, Pair 22; D002895:Chromosomes, Human, Pair 5; D002897:Chromosomes, Human, Pair 7; D004268:DNA-Binding Proteins / Q000235:genetics; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D015479:Leukemia, Myelomonocytic, Acute / Q000235:genetics*; D008297:Male; D009006:Monosomy; D009190:Myelodysplastic Syndromes / Q000235:genetics*; D051788:Myeloid-Lymphoid Leukemia Protein; D011519:Proto-Oncogenes; D014157:Transcription Factors; D014178:Translocation, Genetic / Q000235:genetics*; D014314:Trisomy / Q000235:genetics*; D014998:Y Chromosome
D004268:DNA-Binding Proteins; C497422:KMT2A protein, human; D014157:Transcription Factors; D051788:Myeloid-Lymphoid Leukemia Protein; D011495:Histone-Lysine N-Methyltransferase