title: The non-random dic(9;12) translocation in acute lymphoblastic leukemia is associated with B-progenitor phenotype and an excellent prognosis.
abstract: A dicentric translocation involving the short arms (p) of chromosomes 9 and 12 was identified in 15 of 2303 successfully banded cases of acute lymphoblastic leukemia (ALL) in children, consecutively entered on protocols of the Pediatric Oncology Group (1986-1990) or St Jude Children's Research Hospital (1984 and 1990). The dic(9;12)(p1?1;p1?2) was seen only in patients with a B progenitor cell immunophenotype: the frequency was 0.8% among pre-B cases (4/508) and 0.9% (11/1177) among early pre-B cases. Laboratory and clinical characteristics were similar to those of the general population of children with ALL, with the exception of a marked male preponderance (12/15 cases). Flow cytometric studies revealed a leukemic cell DNA index of 1.0 in all cases. All fifteen patients are in continuous complete remission at a median follow-up duration of 57+ months (range 9-93+ months). These findings suggest that the dic(9;12) is a recurrent chromosomal translocation in pediatric ALL, occurs exclusively in B-progenitor ALL, and unlike other non-random translocations, is associated with an excellent prognosis.
authors.affiliation: Department of Hematology-Oncology, St Jude Children's Research Hospital, Memphis, TN 38101.
authors.forename: H
authors.initials: H
authors.lastname: Mahmoud
authors.forename: A J
authors.initials: AJ
authors.lastname: Carroll
authors.forename: F
authors.initials: F
authors.lastname: Behm
authors.forename: S C
authors.initials: SC
authors.lastname: Raimondi
authors.forename: J
authors.initials: J
authors.lastname: Schuster
authors.forename: M
authors.initials: M
authors.lastname: Borowitz
authors.forename: V
authors.initials: V
authors.lastname: Land
authors.forename: D J
authors.initials: DJ
authors.lastname: Pullen
authors.forename: T J
authors.initials: TJ
authors.lastname: Vietti
authors.forename: W
authors.initials: W
authors.lastname: Crist
mesh_terms: D000293:Adolescent; D001402:B-Lymphocytes; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002881:Chromosomes, Human, Pair 12; D002899:Chromosomes, Human, Pair 9; D006801:Humans; D007223:Infant; D007621:Karyotyping; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics*; D011379:Prognosis; D014178:Translocation, Genetic