title: Multidrug resistance in patients undergoing resective epilepsy surgery is not associated with C3435T polymorphism in the ABCB1 (MDR1) gene.
abstract: OBJECTIVE
  The C3435T polymorphism in the gene coding for P-glycoprotein (ABCB1) has been correlated with drug resistance in patients with epilepsy. However, replication studies have revealed conflicting results and the reason for this is not clear. We investigated the frequency of C3435T polymorphism in epileptic Turkish patients who underwent resective epilepsy surgery and compared our results with healthy controls.
  
  
  METHODS
  DNA samples were obtained from 100 healthy controls and 89 consecutive adult patients who underwent resective brain surgery due to refractory seizures at our epilepsy center. Genotypes for the C3435T polymorphism were determined by PCR and restriction analysis.
  
  
  RESULTS
  Comparison of drug-resistant patients and healthy controls revealed no significant difference in allele frequency (C vs. T; chi(2)=0.015, p=0.90) and genotype frequency (chi(2)=2.05, p=0.36). The findings in the pure hippocampal sclerosis (HS) group (n=73) were not significantly different from control subjects, either (allele frequency: chi(2)=0.29, p=0.59; genotype frequency: chi(2)=2.14, p=0.34).
  
  
  CONCLUSIONS
  Our findings failed to prove an association between C3435T polymorphism and drug resistance in a sample of Turkish patients with refractory epilepsy who underwent resective brain surgery.
authors.affiliation: Hacettepe University, Institute of Neurological Sciences and Psychiatry, Sihhiye 06100, Ankara, Turkey. nesedericioglu@yahoo.com
authors.forename: Nese
authors.initials: N
authors.lastname: Dericioglu
authors.forename: Melih O
authors.initials: MO
authors.lastname: Babaoglu
authors.forename: Umit
authors.initials: U
authors.lastname: Yasar
authors.forename: I Burak
authors.initials: IB
authors.lastname: Bal
authors.forename: Atila
authors.initials: A
authors.lastname: Bozkurt
authors.forename: Serap
authors.initials: S
authors.lastname: Saygi
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000328:Adult; D004252:DNA Mutational Analysis; D018432:Drug Resistance, Multiple / Q000235:genetics*; D004827:Epilepsy / Q000235:genetics* / Q000601:surgery; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D012189:Retrospective Studies
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1