Molecular characterisation of and mutations in a central South African adult acute myeloid leukaemia cohort.

Background: Recognition of molecular abnormalities in acute myeloid leukaemia (AML) has improved our understanding of its biology. and ITD mutations are recurrent in AML and clinically significant. mutations are associated with a favourable prognosis, while ITD mutations are an independent poor prognostic factor in AML.

Objective: This study described the prevalence and molecular characteristics of the and ITD mutations in a newly diagnosed AML patient cohort in central South Africa.

Methods: The study included 40 de novo AML patients. An and ITD multiplex polymerase chain reaction assay was optimised to screen patients for the respective mutations and were confirmed using Sanger sequencing. The prevalence of the and ITD mutations were determined, and mutation-specific characteristics were described in relation to patients' demographic information and AML classifications.

Results: The patients' median age was 38.5 years, with 77.5% ( = 31) of patients being self-proclaimed Black Africans. AML with recurrent genetic abnormalities was most prevalent (57.5%; = 23), of which acute promyelocytic leukaemia (APL) was most common (40.0%; = 16). None of the patients had the mutation. ITD was present in 37.5% (6/16) of APL patients and in one (20.0%) of five AML patients with a t(8;21) translocation. Most patients had an ITD allele ratio of ≥ 50% and ITD lengths of > 39 bp.

Conclusion: ITD mutations were mainly found in APL cases at a similar prevalence as reported in the literature. High ITD allele ratios and long ITD lengths predominated. No mutations were detected.