Rapid progress from MDS to AML in a patient with TMEM91::TAL1 fusion gene: a case report

In the study, we report the first case of an MDS patient carrying the TMEM91::TAL1 fusion gene who rapidly progressed to secondary AML. Through RNA sequencing, we identified the structure diagram of TMEM91::TAL1, subsequently verified via reverse transcriptase-polymerase chain reaction (RT-PCR) and Sanger sequencing. The expression of TMEM91::TAL1 fusion detected by RNA-seq increased with the progression from MDS to AML and decreased with the HSCT, suggesting its involvement in disease progression. The patient remained CR after the fusion was cleared by allo-HSCT, indicating participation of this fusion in disease progression. Therefore, we emphasize the importance of implementing RNA-seq when classical MICM approaches cannot detect pathogenic factors. We also hypothesize that the TMEM91::TAL1 fusion may serve as a potential predictor of progression from MDS to sAML.