A case of NUP98-NSD1 gene fusion resulting from the insertion of a subtelomeric part of chromosome 11p15.4 within the subtelomeric part of 5q35 was detected in a child with acute myeloblastic leukemia. This new case illustrates the importance of using fluorescence in situ hybridization followed by reverse transcriptase-polymerase chain reaction techniques to detect abnormalities involving subtelomeric chromosomal regions.