SCN1B and epilepsy: The reported broad spectrum of epileptic and developmental phenotypes associated with TBC1D24 mutation is unusual, and seen only with a few epilepsy-related genes, mostly with dominant causal mutations (e.g., SCN1A, SCN2A, SCN1B, KCNQ2, KCNT1, PRRT2, DEPDC5, TSC1, and TSC2).