title: Cytogenetic abnormalities in childhood acute myeloid leukaemia: a Nordic series comprising all children enrolled in the NOPHO-93-AML trial between 1993 and 2001.
abstract: Between 1993 and 2001, 318 children were diagnosed with acute myeloid leukaemia (AML) in the Nordic countries. The patient group comprised 237 children < 15 years of age with de novo AML, 42 children < 15 years with Down syndrome (DS) and de novo AML, 18 adolescents 15-18 years of age with de novo AML, and 21 children < 15 years with treatment-related AML (t-AML). The first group was all-inclusive, yielding an annual childhood de novo AML incidence of 0.7/100 000. Cytogenetic analyses were successful in 288 cases (91%), and clonal chromosomal abnormalities were detected in 211 (73%). The distribution of ploidy levels were pseudodiploidy (55%), hyperdiploidy (34%) and hypodiploidy (11%). The most common aberrations (> 2%) were + 8 (23%) (as a sole change in 6.2%), 11q23-translocations, including cryptic MLL rearrangements (22%) [t(9;11)(p21-22;q23) in 11%], t(8;21)(q22;q22) (9.0%), inv(16)(p13q22) (6.2%), -7/7q- (5.2%), and t(15;17)(q22;q12) (3.8%). Except for +8, these abnormalities were rare in group 2; only one DS patient had a t(8;21) and none had 11q23-translocations, t(15;17) or inv(16). In the t-AML group, three cases displayed 11q23-rearrangements, all t(9;11); and there were no t(8;21), t(15;17) or inv(16). Overall, the observed frequencies of t(8;21) and t(15;17) were lower, and frequencies of trisomy 8 and 11q23-translocations higher, than in previous studies. Furthermore, seven abnormalities that were previously reported as only single AML cases were also seen, meaning that der(4)t(4;11)(q26-27;q23), der(6)t(1;6)(q24-25;q27), der(7)t(7;11)(p22;q13), inv(8)(p23q11-12), t(11;17)(p15;q21), der(16)t(10;16)(q22;p13) and der(22)t(1;22)(q21;q13) are now classified as recurrent abnormalities in AML. In addition, 37 novel aberrations were observed, 11 of which were sole anomalies.
authors.affiliation: Departments of Clinical Sciences, Paediatrics, University of Umeå, Sweden. erik.forestier@pediatri.umu.se
authors.forename: Erik
authors.initials: E
authors.lastname: Forestier
authors.forename: Sverre
authors.initials: S
authors.lastname: Heim
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Blennow
authors.forename: Georg
authors.initials: G
authors.lastname: Borgström
authors.forename: Gösta
authors.initials: G
authors.lastname: Holmgren
authors.forename: Kristiina
authors.initials: K
authors.lastname: Heinonen
authors.forename: Johann
authors.initials: J
authors.lastname: Johannsson
authors.forename: Gitte
authors.initials: G
authors.lastname: Kerndrup
authors.forename: Mette Klarskov
authors.initials: MK
authors.lastname: Andersen
authors.forename: Catarina
authors.initials: C
authors.lastname: Lundin
authors.forename: Ann
authors.initials: A
authors.lastname: Nordgren
authors.forename: Richard
authors.initials: R
authors.lastname: Rosenquist
authors.forename: Birgitta
authors.initials: B
authors.lastname: Swolin
authors.forename: Bertil
authors.initials: B
authors.lastname: Johansson
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002869:Chromosome Aberrations; D019457:Chromosome Breakage; D007446:Chromosome Inversion; D005260:Female; D006801:Humans; D007055:Iceland; D007951:Leukemia, Myeloid / Q000235:genetics*; D008297:Male; D012008:Recurrence; D012537:Scandinavian and Nordic Countries; D014178:Translocation, Genetic; D014314:Trisomy