FREQUENCY AND CLINICAL MANIFESTATION OF ETV-RUNX1, BCR-ABL AND AF4-MLL FUSION GENES IN A POPULATION OF NIGERIAN PATIENTS WITH ACUTE LYMPHOBLASTIC LEUKAEMIA

Abstract

Acute lymphoblastic leukaemia (ALL) is a genetic malignant disorder of blood lymphocytes due to mutation in the haemopoietic stem cell or committed precursors. The disease is fatal and its outlook can be improved by early detection and adequate characterization of the malignant clone for purposes of risk stratification and directed targeted therapy.
The clinical and laboratory features in patients diagnosed with ALL are varied and have been associated with specific underlying genetic mutations. Patients diagnosed with ALL in the developing countries like Nigeria have poor outcome and hardly achieve durable remission. This can be attributed to varying factors including inadequate blood and blood product support, late presentation, poverty and perhaps the specific underlying genetic mutation.
This study aims at determining the frequency of ETV6-RUNX1, BCR-ABL1 and AF4-MLLfusion genes in Nigerian patients diagnosed with acute lymphoblastic leukaemia which may have an influence on the observed clinical and laboratory features.
Methods
Peripheral blood samples were collected from 40 Nigerian patients at diagnosis after obtaining oral and written consent and institutional ethical clearance. Realtime polymerase chain reaction (RT-PCR) was used for detection of BCR-ABL1, ETV6-RUNX1 AND AF4-MLLfusion genes and the result compared with the clinical and laboratory features observed in the patients.
Results
Out of 40 patients studied, abnormal fusion genes were detected in 7/40 (17.5%) patients.BCR-ABL1major fusion gene was detected in 5 out of the 7 patients (12.5%) and ETV6/RUNX1 fusion gene was detected in 2 of the patients (5%) whileMLL-AF4 fusion gene was not detected.
There was no relationship between the fusion genes and clinical or laboratory manifestations of the patients however, there appear to be a relationship between the abnormal fusion genes and the ethnic group of the study participants
Conclusion and Recommendation

Interpretation should be given to the result with caution because of the sample size. More studies are needed using larger sample size to detect the genes in ALL