A variant of KCC2 from patients with febrile seizures impairs neuronal Cl- extrusion and dendritic spine formation.
Puskarjov MDepartment of Biosciences, University of Helsinki, Helsinki, Finland Neuroscience Center, University of Helsinki, Helsinki, Finland.
Seja PDepartment of Biosciences, University of Helsinki, Helsinki, Finland Neuroscience Center, University of Helsinki, Helsinki, Finland.
Heron SEEpilepsy Research Program, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia Sansom Institute for Health Research, University of South Australia, Adelaide SA, Australia.
Williams TCEpilepsy Research Program, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
Ahmad FDepartment of Biosciences, University of Helsinki, Helsinki, Finland Neuroscience Center, University of Helsinki, Helsinki, Finland.
Iona XEpilepsy Research Program, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.
Oliver KLDepartment of Medicine, Epilepsy Research Center, The University of Melbourne Austin Health, Melbourne Vic., Australia.
Grinton BEDepartment of Paediatrics, Florey Institute, Royal Children's Hospital The University of Melbourne, Melbourne, Vic., Australia.
Vutskits LDepartment of Anesthesiology, Pharmacology and Intensive Care, University Hospital of Geneva, Geneva, Switzerland.
Scheffer IEDepartment of Medicine, Epilepsy Research Center, The University of Melbourne Austin Health, Melbourne Vic., Australia Department of Paediatrics, Florey Institute, Royal Children's Hospital The University of Melbourne, Melbourne, Vic., Australia.
Petrou SFlorey Institute of Neuroscience and Mental Health and the Center for Neural Engineering, The University of Melbourne, Parkville, Vic., Australia.
Blaesse PDepartment of Biosciences, University of Helsinki, Helsinki, Finland Institute of Physiology I, Westfälische Wilhelms-University Münster, Münster, Germany.
Dibbens LMEpilepsy Research Program, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia Sansom Institute for Health Research, University of South Australia, Adelaide SA, Australia.
Berkovic SFDepartment of Medicine, Epilepsy Research Center, The University of Melbourne Austin Health, Melbourne Vic., Australia.
Kaila KDepartment of Biosciences, University of Helsinki, Helsinki, Finland Neuroscience Center, University of Helsinki, Helsinki, Finland Kai.Kaila@Helsinki.fi.
English
Genetic variation in SLC12A5 which encodes KCC2, the neuron-specific cation-chloride cotransporter that is essential for hyperpolarizing GABAergic signaling and formation of cortical dendritic spines, has not been reported in human disease. Screening of SLC12A5 revealed a co-segregating variant (KCC2-R952H) in an Australian family with febrile seizures. We show that KCC2-R952H reduces neuronal Cl(-) extrusion and has a compromised ability to induce dendritic spines in vivo and in vitro. Biochemical analyses indicate a reduced surface expression of KCC2-R952H which likely contributes to the functional deficits. Our data suggest that KCC2-R952H is a bona fide susceptibility variant for febrile seizures.