Impact of MLL::AF9 Gene Rearrangement on Survival of Acute Myeloid Leukaemia Patients: An Insight into Pakistani Population.

ABSTRACT

OBJECTIVE: To ascertain the frequency of the MLLAF9 gene rearrangement and its association with survival in Pakistani patients suffering from acute myeloid leukaemia (AML). STUDY DESIGN: Analytical study. Place and Duration of the Study Department of Haematology, National Institute of Blood Diseases and Bone Marrow Transplantation, Karachi, Pakistan, from 2015 to 2020. METHODOLOGY: Patients without a history of past AML chemotherapy, aged from 10 to 75 years, were included. Individuals with metastatic cancer, chronic myeloid leukaemia, or other haematological conditions were excluded. Identifying the MLLAF9 gene involved RNA extraction, cDNA synthesis, and Real-time PCR amplification. The Chi-square test was used to examine the relationship between survival and the MLLAF9 mutation. A Welch two-sample t-test was used to evaluate survival days depending on the MLLAF9 gene rearrangement, while ANOVA was used to analyse survival days across various death statuses. RESULTS: The mean age of 130 patients was 36.65 ± 13.01 years, with 64.62% being males. The most common leukaemia type was AML-M2 (n = 32, 24.62%). During the study follow-up, 22.31% were still alive, 40.77% died, and the status of 36.92% were unknown. MLLAF9 gene rearrangement was present in 11.54%. The group with MLLAF9 gene rearrangement had significantly longer mean 'survival days' (1,542.33 ± 926.07) compared to the group without the gene rearrangement (206.42 ± 359.57, p <0.001). CONCLUSION: MLL-AF9 mutation was present in 11.54%. Age and MLLAF9 gene rearrangement were significant predictors of survival in leukaemia patients. KEY WORDS Acute myeloid leukaemia, MLLAF9, Gene rearrangement, Survival.