Acute myeloid leukemia (M2) with a cryptic RUNX1/RUNX1T1 t(1;21;8)(p36;q22;q22) variant
The t(8;21) translocation occurs in 5e12% of acute myeloid leukemia (AML) cases, often occurring in the younger population. This translocation fuses the RUNX1 gene (previously AML1) on chromosome band 21q22 to the RUNX1T1 (previously known as ETO) on 8q22, resulting in a RUNX1/RUNX1T1 hybrid transcript on the derivative chromosome 8 [1,2]. According to the World Health Organization, this type of AML is associated with a favorable prognosis . Variant translocations account for approximately 3e4% of all AML-M2 with RUNX1/RUNX1T1 fusion transcripts , and the clinical consequences of such variants are less clearly defined. Here, we present a case of AML-M2 with a cryptic three-way translocation, t(1;21;8)(p36;q22;q22).