B-cell lymphoblastic leukemia in an adolescent with Dravet syndrome

A 19 year-old adolescent girl with Dravet syndrome, characterized by complex seizure disorder and global developmental delay, presented with B-cell acute lymphoblastic leukemia. The genetic basis for her Dravet syndrome was a pathogenic variant in SCN1A, a sodium channel subunit. SCN1A is chiefly expressed in neuronal tissue, but bioinformatic analysis demonstrated its presence in B cell lineage. One estimate suggested that 10% of children with pediatric cancer have a germline predisposition involving proto-oncogenes or tumor suppressors. This number might be even higher should non-classical genetic variants, such as that encoding a sodium channel subunit, be considered.