Molecular variants of the 1;19 chromosomal translocation in pediatric acute lymphoblastic leukemia (ALL).
The t(1;19)(q23;p13), a non-random chromosome rearrangement associated with childhood pre-B acute lymphoblastic leukemia (ALL), results at molecular level in the hybrid E2A-PBX1 gene. This gene is expressed in a typical set of fusion transcripts and oncogenic chimeric proteins. However, the occurrence of t(1;19) molecular variants has been recently suggested. In an attempt to identify these variants, we analyzed 25 pediatric cases of pre-B cIg+ cell ALL. We used Southern blot analysis to detect E2A gene rearrangements and RT-PCR to detect chimeric E2A-pbx1 transcripts. In addition to seven cases with the molecular pattern usually associated with the t(1;19), we identified three molecular variants. In one case, a variant E2A-pbx1 transcript showed 27 additional base pairs inserted in frame at the junction site. In two cases, Southern blot evidenced the expected E2A gene rearrangements. However, extensive RT-PCR analysis failed to detect any E2A-pbx1 transcript. These findings led us to hypothesize that a gene other than PBX1 might be involved in these 1;19 variant translocations.
Privitera
E
E
Dipartimento di Genetica e di Biologia dei Microrganismi, Università di Milano, Italy.
Luciano
A
A
Ronchetti
D
D
Aricò
M
M
Santostasi
T
T
Basso
G
G
Biondi
A
A
D001483:Base Sequence; D002648:Child; D002878:Chromosomes, Human, Pair 1; D002888:Chromosomes, Human, Pair 19; D015321:Gene Rearrangement; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis*; D016133:Polymerase Chain Reaction; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000032:analysis*; D014178:Translocation, Genetic
D009363:Neoplasm Proteins; D011993:Recombinant Fusion Proteins