title: Association of MDR1 (C3435T) polymorphism and resistance to carbamazepine in epileptic patients from Turkey.
abstract: OBJECTIVE
  We investigated the prevalence of this multidrug resistance 1 gene (MDR1) polymorphism in drug-responsive versus drug-resistant epilepsy patients treated with carbamazepine (CBZ), which is a substrate of this protein.
  
  
  METHODS
  We genotyped the C3435T variant of MDR1 in 97 patients treated with CBZ monotherapy who had been on stable doses for more than 1 month. Our control group included 174 healthy individuals. Plasma CBZ concentrations were also measured using fluorescence polarization immunoassay.
  
  
  RESULTS
  We could not demonstrate any statistically significant relationship with the genotypes among drug-resistant patients (n = 44). The frequency of the homozygous mutant (TT) genotype was 15% in drug-responsive patients, 11.3% in drug-resistant patients and 25.8% in the control group. We also did not observe any significant correlation between the presence of a specific allele and CBZ plasma level/dose index.
  
  
  CONCLUSIONS
  Our study did not support any significant association between the MDR1 (C3435T) polymorphism and resistance to CBZ in epilepsy patients from Turkey.
authors.affiliation: Department of Genetics, Institute for Experimental Medical Research, Istanbul Medical Faculty, Istanbul University, Istanbul, Turkey.
authors.forename: Gulay Oner
authors.initials: GO
authors.lastname: Ozgon
authors.forename: Nerses
authors.initials: N
authors.lastname: Bebek
authors.forename: Gunay
authors.initials: G
authors.lastname: Gul
authors.forename: Naci
authors.initials: N
authors.lastname: Cine
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000328:Adult; D000927:Anticonvulsants / Q000097:blood / Q000627:therapeutic use; D002220:Carbamazepine / Q000097:blood / Q000627:therapeutic use; D004351:Drug Resistance / Q000235:genetics*; D004827:Epilepsy / Q000188:drug therapy / Q000235:genetics*; D005260:Female; D016231:Fluorescence Polarization Immunoassay / Q000379:methods; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D014421:Turkey
chemical_list: C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000927:Anticonvulsants; D002220:Carbamazepine