ELF4 is fused to ERG in a case of acute myeloid leukemia with a t(X;21)(q25-26;q22).

We report a novel chromosomal translocation in AML, t(X;21)(q25-26;q22), resulting in a fusion transcript between two ETS domain family members, ELF4 (at Xq25) and ERG (at 21q22). ERG has been associated previously with other fusion partners, specifically FUS and EWSR1, and implicated in both AML and Ewing's sarcoma. RT-PCR analysis of RNA isolated from bone marrow samples from the patient demonstrates that the translocation occurs within intron 1 of ERG isoform 1 (ERG-1) and intron 2 of ELF4 resulting in an in-frame fusion joining exon 2 from ELF4 with exon 2 of ERG. This is the first reported case of an ELF4-ERG fusion and identification of the specific ERG exon involved in the fusion that differentiates ERG isoforms. In addition, this case also directly implicates a new role for ELF4 in cancer.