Schematic representation of the inv(16).

Both CBFB and MYH11 genes are transcribed in the centromeric to telomeric direction. The inversion fuses the 5′ end of the CBFB gene, located on 16q22, upstream of the 3′ end of MYH11 on 16p13. The reciprocal fusion geneMYH11/CBFB is also generated in most of the cases. However, deletion of MYH11 sequences upstream of the 5′ breakpoint is reported in some cases.29