Insertion of MLL sequences into chromosome band 5q31 results in an MLL-AF5Q31 fusion and is a rare but recurrent abnormality associated with infant leukemia.
MLL gene rearrangements leading to production of MLL fusion proteins are commonly detected in infant leukemia patients; the most common MLL fusion associated with infant leukemia is the MLL-AF4 fusion. A single case of chromosomal rearrangement leading to production of an MLL fusion with AF5Q31, a gene structurally similar to AF4, has been detected recently in the malignant cells of an infant leukemia patient. We have identified a second case of MLL-AF5Q31 fusion, arising from an insertion of MLL sequences into chromosome 5, also in an infant leukemia patient. Because MLL and AF5Q31 are transcribed in opposite orientations, a simple balanced chromosomal translocation cannot produce a fusion protein, and complex chromosomal rearrangements such as insertions and inversions are required to produce an MLL-AF5Q31 fusion protein. This report demonstrates that chromosomal insertion of MLL sequences is a rare but recurrent abnormality associated with infant leukemia.
Deveney
Ramona
R
Genetics Branch, Center for Cancer Research, National Cancer Institute, Gaithersburg, Maryland 20892, USA.
Chervinsky
David S
DS
Jani-Sait
Sheila N
SN
Grossi
Mauro
M
Aplan
Peter D
PD
D001483:Base Sequence; D002869:Chromosome Aberrations; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D017809:Fatal Outcome; D011495:Histone-Lysine N-Methyltransferase; D006801:Humans; D007223:Infant; D015448:Leukemia, B-Cell / Q000188:drug therapy / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000235:genetics*; D051788:Myeloid-Lymphoid Leukemia Protein; D009687:Nuclear Proteins / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy / Q000235:genetics*; D011519:Proto-Oncogenes; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors
D004268:DNA-Binding Proteins; C497422:KMT2A protein, human; D009687:Nuclear Proteins; D015514:Oncogene Proteins, Fusion; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; D051788:Myeloid-Lymphoid Leukemia Protein; C081449:AFF1 protein, human; D011495:Histone-Lysine N-Methyltransferase