Intragenic amplification of PAX5: a novel subgroup in B-cell precursor acute lymphoblastic leukemia?
Abstract
B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is the most common childhood malignancy, characterized by a wide spectrum of genetic abnormalities, which are used in risk stratification for treatment. PAX5 encodes a transcription factor, which plays a key role in B-cell commitment and maintenance and is frequently (20% to 35%) deleted or mutated in BCP-ALL.
Germline PAX5 mutations also occur in familial ALL. Furthermore, chromosomal rearrangements involving PAX5 result in the expression of potentially oncogenic PAX5 fusion genes.
Here we present a subset of patients with BCP-ALL lacking the major cytogenetic abnormalities (ETV6-RUNX1, BCR-ABL1, and TCF3-PBX1 fusions, high hyperdiploidy, near-haploidy, low hypodiploidy, MLL rearrangements, or intrachromosomal amplification of chromosome 21) with intragenic amplifications of PAX5 (PAX5AMP).