In AML, with genetic abnormalities, the presence of the following chromosome abnormalities can be help reach the diagnosis.
- t(15:17) – Acute promyelocytic leukaemia (APL)
These chromosome abnormalities confirm the diagnosis even if the patients’ percentage of immature leukaemia cells is less than 20%.
In APL, there is a reciprocal translocation between chromosome 15 and chromosome 17. The promyelocytic leukaemia (PML) gene in chromosome 15 and the retinoic acid receptor alpha (RARA) gene in chromosome 17 swap places. These genes fuse to become the PML-RARA gene in the resulting chromosomes (Figure 7).
Figure 7 Reciprocal chromosome translocation in APL
The PML-RARA gene makes APL a distinct type of AML that has a separate treatment and prognosis.
The symptoms, signs, diagnosis and treatment of APL can be found in our booklet at shop.leukaemiacare.org.uk