Statistics (Phenotypes)

Prevalence of the different channelepsy phenotypes as well as other neurological disorders associated with defects in SCN1A. 

Note: These statistics are based on all data on this web site excluding the mutations listed under "New"

  N = 
SMEI & derivatives   
 SMEI (severe myoclonic epilepsy in infancy, Dravet’s syndrome)257(71.6 %)
 SMEB (SMEI-borderland)17(4.7 %)
 SMEB-M (SMEB without myoclonus)3(0.8 %)
 SMEB-SW (SMEB without generalized spike-wave)11(3.1 %)
 SMEB-O (SMEB lacking more than one typical SMEI characteristic)10(2.8 %)
 ICEGTC (intractable childhood epilepsy with generalized tonic-clonic seizures)9(2.5 %)
 aSMEI (atypical SMEI)2(0.6 %)
 Subtotal302(86.1 %)
GEFS+ & derivatives   
 GEFS+ (generalized epilepsy with febrile seizures, plus)21(5.8 %)
 FS (febrile seizures)3(0.8 %)
 Subtotal24(6.7 %)
Other epileptic disorders  
 CGE (cryptogenic generalized epilepsy)7(1.9 %)
 CFE (cryptogenic focal epilepsy)4(1.1 %)
 MAE (myoclonic astatic epilepsy, Doose syndrome)3(0.8 %)
 SIGEI (severe idiopathic generalized epilepsy of infancy)2(0.6 %)
 RE (Rasmussen’s encephalitis)1(0.3 %)
 IS (infantile spasms, West syndrome)1(0.3 %)
 LGS (Lennox-Gastaut syndrome)1(0.3 %)
 Subtotal19(5.3 %)
Non-epileptic disorders  
 FA (familial autism)3(0.8 %)
 FHM (familial hemiplegic migraine)3(0.8 %)
 PS (Panayiotopoulos syndrome)1(0.3 %)
 Subtotal7(1.9 %)

Percentages were based on N = 359, which is the total number of different phenotypes reported for the listed variants. Some variants are listed with more than one phenotype owing to differing diagnoses between publications.