P358: COMPREHENSIVE DIAGNOSTICS OF ACUTE LYMPHOBLASTIC LEUKEMIA BY WHOLE TRANSCRIPTOME RNA SEQUENCING

Abstract

Background: Acute lymphoblastic leukemia (ALL) has genetic heterogeneity, which is helpful to clinical diagnosis, prognosis stratification and treatment guidance. Gene aberrations are structurally diverse and are currently analyzed by different assays. Aims: This study aims to establish a single and comprehensive platform for ALL diagnosis by whole transcriptome RNA sequencing (WTRS), which can detect fusion, mutations and expression. Methods: We analyzed the data of 70 ALL patients by WTRS. Results: We found that the fusion coincidence rate of WTRS was 100% (19 / 19) comparing with quantitative real-time polymerase chain reaction (qPCR). At the same time, six rare fusion forms were detected, which increased the diagnosis rate of fusion gene from 27% (19 / 70) to 36% (25 / 70). The expression of CRLF2 gene in 5 cases was consistent with that of qPCR. Seven cases with IKZF1 gene skipping identified by qPCR were consistent with the results of WTRS, and a rare IKZF1 deletion subtype was detected. Of the 51 genes associated with ALL, 100% (103/103) gene mutation at the RNA level by WRTS is consistent with the results at the DNA level by targeted DNA sequencing (except 3 splice site mutations and 4 mutations with poor coverage). Summary/Conclusion: In conclusion, the standardization of experimental operation and improvement of biological information pipline of WRTS are very important factors in its use in standard diagnostic procedures. WRTS has the potential to provide accurate comprehensive diagnostic information for clinic and further improve the ALL diagnostic rate.