KMT2A and glycogen storage disease VI: Most of the patients (68%) showed at least one of the conventional clinical risk factors, such as age (<1 year or ≥10 years), WBC count (≥50×109/L), presence of the BCR-ABL1 fusion or MLL gene alteration, extramedullary disease, poor prednisone response (PPR) and T cell immunophenotype.