Somatic mutations in WT1 in T-ALL. (A) Schematic representation of WT1 mutations identified in primary T-ALL samples. (B-F) DNA sequence chromatograms showing representative examples of different mutations in WT1. (B) Frameshift truncating mutation in exon 7 of WT1. (C) Nonsense point mutation in exon 7 of WT1. (D) Acceptor site mutation affecting exon 7 of WT1. (E) Frameshift truncating mutation in exon 1 of WT1. (F) Missense mutations involving R462 in the DNA-binding domain of WT1.