The vast majority of mutations responsible for epilepsy syndromes such as genetic
epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS) occur in the
gene encoding the type 1 alpha subunit of neuronal voltage-gated sodium channel (SCN1A).63
individuals presenting with either DS or GEFS + syndrome phenotype were screened for
SCN1A gene mutation using Sanger sequencing and multiplex ligation-dependent probe
amplification (MLPA).Our research study identified 15 novel pathogen mutations in
the SCN1A gene of which 12 appeared to be missense mutations with addition of two
frameshift-deletions and one in-frame deletion. The distribution of clinical phenotypes
in patients carrying SCN1A mutations was as follows: twelve patients had classical
DS, three patients had GEFS + syndrome and two relatives of DS patients were suffering
from febrile seizures.Our study highlights the phenotypic and genotypic heterogeneities
of DS and GEFS + with the important aim of gaining a deeper understanding of SCN1A-related
disorders. This study also represents the first genetic analysis of the SCN1A gene
in a Hungarian cohort with the DS and GEFS + syndrome phenotype.
