Role of the sodium channel SCN9A in genetic epilepsy with febrile seizures plus and Dravet syndrome
John C Mulley, Bree Hodgson, Jacinta M McMahon, Xenia Iona, Susannah Bellows, Saul A Mullen, Kevin Farrell, Mark Mackay, Lynette Sadleir, Andrew Bleasel, Deepak Gill, Richard Webster, Elaine C Wirrell, Michael Harbord, Sanyjay Sisodiya, Eva Andermann, Sara Kivity, Samuel F Berkovic, Ingrid E Scheffer, Leanne M Dibbens
EPILEPSIA | WILEY | Published : 2013
Mutations of the SCN1A subunit of the sodium channel is a cause of genetic epilepsy with febrile seizures plus (GEFS(+) ) in multiplex families and accounts for 70-80% of Dravet syndrome (DS). DS cases without SCN1A mutation inherited have predicted SCN9A susceptibility variants, which may contribute to complex inheritance for these unexplained cases of DS. Compared with controls, DS cases were significantly enriched for rare SCN9A genetic variants. None of the multiplex febrile seizure or GEFS(+) families could be explained by highly penetrant SCN9A mutations.
We are indebted to the patients and their families for contributing to our research. We thank the National Health and Medical Research Council of Australia, Thyne-Reid Charitable Trusts, MS McLeod Foundation, and SA Pathology for support; Robert Schultz and Beverley Johns for technical assistance; Simon Harvey for clinical information on patients; and two anonymous referees for their rigorous comments and constructive suggestions.