Karyotype showing classic translocation t(15;17)(q24;q21)

Karyotype showing classic translocation t(15;17)(q24;q21)
Author: Mr Anil Kumar Yadav, Dr Manorama Bhargava, India
Category: Myeloid Neoplasms and acute leukemia (WHO 2016) > Acute Myeloid Leukemia > Acute Myeloid Leukemia with recurrent genetic abnormalities > AML with t(15;17)(q22;q12); PML-RARA (and variants)
Published Date: 07/03/2018

We present a 38 years old male patient showing t(15;17)(q24;q21) by karyotype, his PB findings are: Hb: 11.1 g/dl, Platelets: 1,10,000 /cu mm and TLC: 500/cu mms. The Peripheral blood, Bone marrow aspirate and biopsy features are consistent with Acute Promyelocytic Leukemia (APML). IPT showed AML.

Cytogenetic analysis of unstimulated bone marrow aspirate culture (at 370C for 17 hours by using colcemid) shows balanced reciprocal translocation between long arms of chromosome 15 and 17. This is consistent with Acute Promyelocytic leukemia (APML). t(15;17) involving PML on chromosome 15 and RARA on chromosome 17. However due to cryptic submicroscopic insertion of RARA into the PML gene, it cannot be seen by karyotyping in rare cases. Mostly it is present as sole abnormality but it can be seen with +8, deletion 7q, deletion 9q or other myeloid abnormalities.

Note- As a arbitrary placement of GTG banded chromosomes worldwide, derivative chromosomes are placed in the right side of homologous pair, which is highlighted in circle.