ABCB1 gene polymorphisms is not associated with drug-resistant epilepsy in Romanian children

Background: P-glycoprotein (P-gp), a drug efflux transporter, encoded by the gene MDR1 ABCB1 multidrug resistant, reduces the penetration through the brain by the AEDs. Overexpression of Pgp in blood-brain barrier in epileptic patients play an important rol in pharmacoresistance. The aim of this study was to evaluate a possible association between C1236T and G2677T ABCB1 gene polymorphisms and drug-resistant epilepsy in Romanian children. Material and Methods: A total of 194 children with epilepsy hospitalized in the Paediatric Neurology and Psychiatry Clinic in Tirgu Mures and 153 healthy controls were included in this study. Of the initial group, those cases that met the criteria for idiopathic and cryptogenic epilepsies (114 cases) were stratified in 31drug-resistant and 83 drug-responsive patients. The C1236T and G2677T genetic polymorphisms were assessed by RFLP-PCR (polymerase chain-restriction fragment length polymorphism) followed by gel electrophoresis. Results: Molecular analysis of ABCB1 gene polymorphism identified 1236CT heterozygous to be highly repre-sented in drug-responsive group, with a p value of 0.001. Also, in idiopathic epilepsy subgroups (with partial and generalized type of seizures), in case of 1236TT and CT genotypes we found highly significant differences between drug-responsive patients and those resistant to antiepileptic treatment (p-0.003 and p-0.002 respectively). No association between G2677T polymorphism and total epilepsy was found. Conclusions: Our results show that MDR1 C1236T and G2677T polymorphisms are not associated with drug-resistant epilepsy in the study population, but 1236TT and 1236CT genotype variants and also 2677TT were found to be significantly associated with drug-responsive idiopathic epilepsy.