title: Association of SCN1A gene polymorphism with antiepileptic drug responsiveness in the population of Thrace, Greece.
abstract: BACKGROUND
  The aim was to examine the influence of the SCN1A gene polymorphism IVS5-91 rs3812718 G>A on the response to antiepileptic drugs (AEDs) in monotherapy or polytherapy.
  
  
  METHODS
  Two hundred epilepsy patients and 200 healthy subjects were genotyped for SCN1A IVS5-91 rs3812718 G>A polymorphism using TaqMan assay. Patients were divided into drug-responsive and drug-resistant patients. The drug-responsive group was further studied, comparing monotherapy in maximum and minimum doses and monotherapy-responsive and -resistant groups.
  
  
  RESULTS
  There were no statistically significant differences in the allelic frequencies and genotype distributions between patients and controls (p= 0.178). The distribution of SCN1A IVS5-91 rs3812718 G>A genotypes was similar between drug-responsive and drug-resistant patients (p= 0.463). The differences in genotype distributions (A/A or A/G vs. G/G) between monotherapy-responsive and -resistant groups were statistically significant (p= 0.021). Within the monotherapy-responsive group, patients with the A/A or A/G genotype needed higher dose AEDs than patients with the G/G genotype (p= 0.032). The relative risk for generalized epilepsy due to A-containing genotypes was of marginal statistical significance when compared with the G/G genotype (p= 0.05).
  
  
  CONCLUSIONS
  Overall, our findings demonstrate an association of SCN1A IVS5-91 rs3812718 G>A polymorphism with AED responsiveness in monotherapy without evidence of an effect on drug-resistant epilepsy.
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Christina
authors.initials: C
authors.lastname: Angelopoulou
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Stavroula
authors.initials: S
authors.lastname: Veletza
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Heliopoulos
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Vadikolias
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Grigorios
authors.initials: G
authors.lastname: Tripsianis
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Chrysa
authors.initials: C
authors.lastname: Stathi
authors.affiliation: Department of Neurology, Democritus University of Thrace, Alexandroupolis, Greece.
authors.forename: Charitomeni
authors.initials: C
authors.lastname: Piperidou
keywords: SCN1A; antiepileptic drugs; gene polymorphism; resistant epilepsy; responsiveness