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.