Referenced in: none

Automatically associated channels: Slo2

Title: De novo gain-of-function KCNT1 channel mutations cause malignant migrating partial seizures of infancy.

Authors: Giulia Barcia, Matthew R Fleming, Aline Deligniere, Valeswara-Rao Gazula, Maile R Brown, Maeva Langouet, Haijun Chen, Jack Kronengold, Avinash Abhyankar, Roberta Cilio, Patrick Nitschke, Anna Kaminska, Nathalie Boddaert, Jean-Laurent Casanova, Isabelle Desguerre, Arnold Munnich, Olivier Dulac, Leonard K Kaczmarek, Laurence Colleaux, Rima Nabbout

Journal, date & volume: Nat. Genet., 2012 Nov , 44, 1255-9

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23086397

Abstract
Malignant migrating partial seizures of infancy (MMPSI) is a rare epileptic encephalopathy of infancy that combines pharmacoresistant seizures with developmental delay. We performed exome sequencing in three probands with MMPSI and identified de novo gain-of-function mutations affecting the C-terminal domain of the KCNT1 potassium channel. We sequenced KCNT1 in 9 additional individuals with MMPSI and identified mutations in 4 of them, in total identifying mutations in 6 out of 12 unrelated affected individuals. Functional studies showed that the mutations led to constitutive activation of the channel, mimicking the effects of phosphorylation of the C-terminal domain by protein kinase C. In addition to regulating ion flux, KCNT1 has a non-conducting function, as its C terminus interacts with cytoplasmic proteins involved in developmental signaling pathways. These results provide a focus for future diagnostic approaches and research for this devastating condition.