Ph1-positive, bcr-negative acute leukemias: clustering of breakpoints on chromosome 22 in the 3' end of the BCR gene first intron.
About 50% of the Philadelphia-positive acute leukemias undergo molecular rearrangements outside the now classical bcr sequence (or M-BCR-1) rearranged in chronic myeloid leukemia (CML). Most of the breakpoints on chromosome 22 have been shown to be clustered in a 10.8-kb region of the first intron of the BCR gene (called bcr2 or m-BCR-1). In this report we examined two cases of Ph1 acute lymphoblastic leukemia in adult patients that exhibited breakpoints in a 5-kb segment of the BCR gene first intron, 16 kb upstream of the previously described cluster, suggesting the possibility of a second minor breakpoint cluster. In addition, the breakpoints on chromosome 9 were located in a region just 5' of the c-abl exon la.
Chen
S J
SJ
INSERM U 301, Hôpital Saint-Louis, Paris, France.
Chen
Z
Z
Hillion
J
J
Grausz
D
D
Loiseau
P
P
Flandrin
G
G
Berger
R
R
D002892:Chromosomes, Human, Pair 22; D002899:Chromosomes, Human, Pair 9; D015321:Gene Rearrangement; D006801:Humans; D007438:Introns; D015470:Leukemia, Myeloid, Acute / Q000235:genetics* / Q000473:pathology; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D011519:Proto-Oncogenes; D015183:Restriction Mapping; D014178:Translocation, Genetic