TP53 variants underlying pediatric low-hypodiploidy B-cell acute lymphoblastic leukemia demonstrate diverse origins and may persist as a hematopoietic clone in remission

Pediatric low-hypodiploidy B-cell acute lymphoblastic leukemia (LH-ALL) with TP53 variants has been proposed to be considered a manifestation of Li-Fraumeni syndrome (LFS). However, our study demonstrates that of the majority the pathogenic variants in the TP53 gene are somatic (70.5%), and only 12.5% of patients with germline fulfilled the criteria of LFS. We also describe the first case of hypodiploid BCP-ALL with a mosaic pathogenic mutation in TP53 and the first case of the persistence of clonal hematopoiesis with the T & Rcy;53 gene mutation in the child during 3-year minimal residual disease-negative remission, similar to what has been described in adults.