Epilepsy

Figure 1.   Epilepsy-causing mutations in SCN1A. Schematic diagram of the Nav1.1 sodium channel α subunit and associated β1 and β2 subunits. The Nav1.1 α subunit is associated noncovalently with β1 or β3, and it is associated via a disulfide linkage with either β2 or β4. The α subunit consists of four homologous domains (I–IV), each containing six transmembrane segments (S1–S6). The voltage-sensing S4 segment has multiple, positively charged amino acids (+), and the intracellular loop between domains III and IV functions as the inactivation gate, containing four residues (IFMT) that interact with the inactivation docking site. The GEFS+ mutations that are mentioned in this review are indicated by filled circles. A complete list of the epilepsy-causing mutations in SCN1A can be found at http://web.scn1a.info (Lossin, 2009) andhttp://www.molgen.ua.ac.be/SCN1AMutations/ (Claes et al., 2009).

Types

PDS

Na channel mutations

SCNA1 mutations- functional effects