Dravet syndrome or genetic (generalized) epilepsy with febrile seizures plus?

2009 ◽  
Vol 31 (5) ◽  
pp. 394-400 ◽  
Author(s):  
Ingrid E. Scheffer ◽  
Yue-Hua Zhang ◽  
Floor E. Jansen ◽  
Leanne Dibbens
2013 ◽  
Vol 142 (6) ◽  
pp. 641-653 ◽  
Author(s):  
Linda Volkers ◽  
Kristopher M. Kahlig ◽  
Joost H.G. Das ◽  
Marjan J.A. van Kempen ◽  
Dick Lindhout ◽  
...  

Generalized epilepsy with febrile seizures plus (GEFS+) is an early onset febrile epileptic syndrome with therapeutic responsive (a)febrile seizures continuing later in life. Dravet syndrome (DS) or severe myoclonic epilepsy of infancy has a complex phenotype including febrile generalized or hemiclonic convulsions before the age of 1, followed by intractable myoclonic, complex partial, or absence seizures. Both diseases can result from mutations in the Nav1.1 sodium channel, and initially, seizures are typically triggered by fever. We previously characterized two Nav1.1 mutants—R859H (GEFS+) and R865G (DS)—at room temperature and reported a mixture of biophysical gating defects that could not easily predict the phenotype presentation as either GEFS+ or DS. In this study, we extend the characterization of Nav1.1 wild-type, R859H, and R865G channels to physiological (37°C) and febrile (40°C) temperatures. At physiological temperature, a variety of biophysical defects were detected in both mutants, including a hyperpolarized shift in the voltage dependence of activation and a delayed recovery from fast and slow inactivation. Interestingly, at 40°C we also detected additional gating defects for both R859H and R865G mutants. The GEFS+ mutant R859H showed a loss of function in the voltage dependence of inactivation and an increased channel use-dependency at 40°C with no reduction in peak current density. The DS mutant R865G exhibited reduced peak sodium currents, enhanced entry into slow inactivation, and increased use-dependency at 40°C. Our results suggest that fever-induced temperatures exacerbate the gating defects of R859H or R865G mutants and may predispose mutation carriers to febrile seizures.


Author(s):  
Elisa Pasquetti ◽  
Manuela Lo Bianco ◽  
Federica Sullo ◽  
Francesca Patanè ◽  
Laura Sciuto ◽  
...  

AbstractOne of the first reported genes associated with epilepsy was SCN1B, which encodes for β-subunit of voltage-gated sodium channel of excitable cells and it is critical for neuronal function in both central and peripheral nervous system. β-subunits modulate the expression levels and functional properties of sodium channels and though their immunoglobulin domains may mediate interactions between channels and other proteins. Traditionally, SCN1B mutations were associated with generalized epilepsy with febrile seizures plus, a familial epilepsy syndrome characterized by heterogeneous phenotypes including febrile seizures (FS), febrile seizures plus (FS + ), mild generalized epilepsies, and severe epileptic encephalopathies. Throughout the years, SCN1B mutations have been also associated with Dravet syndrome and, more recently, with developmental and epileptic encephalopathies, expanding the spectrum associated with this gene mutations to more severe phenotypes.


Neurology ◽  
2017 ◽  
Vol 89 (12) ◽  
pp. 1210-1219 ◽  
Author(s):  
Yue-Hua Zhang ◽  
Rosemary Burgess ◽  
Jodie P. Malone ◽  
Georgie C. Glubb ◽  
Katherine L. Helbig ◽  
...  

Objective:Following our original description of generalized epilepsy with febrile seizures plus (GEFS+) in 1997, we analyze the phenotypic spectrum in 409 affected individuals in 60 families (31 new families) and expand the GEFS+ spectrum.Methods:We performed detailed electroclinical phenotyping on all available affected family members. Genetic analysis of known GEFS+ genes was carried out where possible. We compared our phenotypic and genetic data to those published in the literature over the last 19 years.Results:We identified new phenotypes within the GEFS+ spectrum: focal seizures without preceding febrile seizures (16/409 [4%]), classic genetic generalized epilepsies (22/409 [5%]), and afebrile generalized tonic-clonic seizures (9/409 [2%]). Febrile seizures remains the most frequent phenotype in GEFS+ (178/409 [44%]), followed by febrile seizures plus (111/409 [27%]). One third (50/163 [31%]) of GEFS+ families tested have a pathogenic variant in a known GEFS+ gene.Conclusion:As 37/409 (9%) affected individuals have focal epilepsies, we suggest that GEFS+ be renamed genetic epilepsy with febrile seizures plus rather than generalized epilepsy with febrile seizures plus. The phenotypic overlap between GEFS+ and the classic generalized epilepsies is considerably greater than first thought. The clinical and molecular data suggest that the 2 major groups of generalized epilepsies share genetic determinants.


1999 ◽  
Vol 65 (4) ◽  
pp. 1078-1085 ◽  
Author(s):  
Stéphanie Baulac ◽  
Isabelle Gourfinkel-An ◽  
Fabienne Picard ◽  
Myriam Rosenberg-Bourgin ◽  
Jean-François Prud'homme ◽  
...  

2003 ◽  
Vol 53 (1-2) ◽  
pp. 107-117 ◽  
Author(s):  
Patrick Cossette ◽  
Andrew Loukas ◽  
Ronald G. Lafrenière ◽  
Daniel Rochefort ◽  
Eric Harvey-Girard ◽  
...  

2002 ◽  
Vol 22 (24) ◽  
pp. 10699-10709 ◽  
Author(s):  
Laurence S. Meadows ◽  
Jyoti Malhotra ◽  
Andrew Loukas ◽  
Veena Thyagarajan ◽  
Kristin A. Kazen-Gillespie ◽  
...  

2018 ◽  
Vol 07 (04) ◽  
pp. 148-151 ◽  
Author(s):  
Fahad A. Bashiri ◽  
Abrar Hudairi ◽  
Malak Al Ghamdi ◽  
Adel A. Mahmoud

AbstractNeonatal seizures may have multiple causes including metabolic and genetic etiologies. If a genetic diagnosis is known, it can guide the physician to choose the most appropriate treatment modality. SCN2A mutation is a rare cause of epileptic encephalopathy in the neonatal age group. It has a wide phenotypic variation, ranging from benign familial epilepsy to a malignant form of epilepsy. This mutation has been associated with Ohtahara syndrome, migrating focal seizures of infancy, West syndrome, Lennox–Gastaut syndrome, and generalized epilepsy with febrile seizures plus. We present the case of a newborn girl who presented with multiple types of seizures, starting at the age of 3 days. Our initial investigations were not able to identify the etiology of her intractable seizures. Whole exome sequencing confirmed an SCN2A mutation. Various antiepileptic drugs (AEDs), including phenobarbitone, phenytoin, levetiracetam, topiramate, vigabatrin, carbamazepine, clonazepam, and mexiletine, were tried. However, none provided an optimal response. She ultimately showed a dramatic response to the ketogenic diet (KD). This report highlights the effectiveness of the KD as a treatment modality for SCN2A mutation-related epileptic encephalopathy, particularly when seizures are intractable and unresponsive to conventional AEDs.


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