Acute myelogenous leukaemia with t(8;21) translocation of normal cell origin in mosaic Down's syndrome with isochromosome 21q

Abstract

Summary. We report a 13-year-old girl with Down's syndrome (DS) having a mosaic karyotype of 46,XX/46,XX, ¹21,þi(21q), who developed acute myelogenous leukaemia (AML) (FAB M1). The t(8;21) translocation generating a AML1/MTG8 chimaeric gene of her blasts was demonstrated by cytogenetic analysis and reverse transcription-polymerase chain reaction. Interestingly, the leukaemic clone with t (8;21) did not have isochromosome 21q, indicating that the blasts were of normal cell origin. These findings suggest that, in older patients with DS, 21 trisomy cells have no greater predisposition to develop AML than normal karyotypic cells.

Myeloid leukemia in children 4 years or older with Down syndrome often lacks GATA1 mutation and cytogenetics and risk of relapse are more akin to sporadic AML

“…AML recurrent cytogenetic abnormalities (t(8;21), t(15;17), inv(16) and MLL aberrations) are otherwise very uncommon in DS and have been reported only occasionally in older children or adults with DS. [11][12][13] These cases share the common morphologic and cytogenetic features of AML in non-DS individuals. Such cases may represent sporadic AML in an individual with DS.…”

Preserved High Probability of Overall Survival with Significant Reduction of Chemotherapy for Myeloid Leukemia in Down Syndrome: A Nationwide Prospective Study in Japan

“…However, an optimal therapeutic approach for these “atypical” ML‐DS has not been established. Because there are a few case reports of the patients older than 4 years old in Japan who were successfully treated with less intensive regimen, patients older than 4 years old were eligible for this AML‐D05 study.…”

The Management of Neoplastic Disorders of Haematopoeisis in Children with Down's Syndrome

“…However, there are rare cases in which the AML has a translocation or deletion unrelated to the clone in the TMD. The morphology is not M7, and the age is usually over 5 years ( Morgan et al , 1985 ; Wang et al , 1987 ; Sato et al , 1997 ; Yamaguchi et al , 1997; Kounami et al , 1998 ). These clonally unrelated cases implicate host factors that predispose to the development of myeloid leukaemia rather than clonal evolution of residual leukaemic cells.…”