The Ups and Downs When TLX-1 and Other Transcriptional Modulators Abound: A Case of T-ALL with a Transcriptionally Complex Set of Mutations.

Abstract

Objectives: Acute T-lymphoblastic leukemia (T-ALL) is a malignancy of immature T-cells in children and adults and although it occurs less frequently than B-ALL, it carries a worse prognosis, especially after relapse. Molecular characterization and subtyping of T-ALL has begun to reveal vital insights into the complex biology of T-ALL and has prognostic and therapeutic implications. We present a case of a 19-year-old male who was found to have an early cortical phenotype T-ALL with multiple cytogenetic and somatic mutations including t(10;14) TLX-1 translocation, 9p22 CDKN2A deletion and missense mutations in PHF6, NOTCH-1, and FBXW7. Characterization of the significance of these mutations reveals that PHF6 mutations occur more frequently in adult males in association with TLX-1 translocations and early cortical phenotypes with NOTCH-1 activating mutations. We show mechanistically that these alterations occur in concert with one another to drive cell growth, cell survival and cell cycle progression. While still in development, further characterization of T-ALL is essential to provide more prognostic and therapeutically useful information.