Role of ABCB1 Variants on Postoperative Seizure Recurrence in Patients with AED-Resistant Temporal Lobe Epilepsy (P05.079)

Abstract

Objective: To investigate the role of single nucleotide polymorphisms (SNPs) in ATP-binding cassette family gene, ABCB1 in predicting the postoperative seizure recurrence in antiepileptic drug (AED)-resistant temporal lobe epilepsy (TLE) patients from Southern India. Background Even though several electro-clinical and imaging characteristics could predict postoperative seizure outcome in patients with drug-resistant TLE patients, none of them have consistently been shown to be associated with the outcome. The genetic factors can play a critical role in attaining postoperative seizure freedom, and if identified, they could serve as biological markers of immense clinical importance. Increased P-glycoprotein expression in the temporal lobe has been shown to be associated with AED resistance and seizure recurrence after surgery. We hypothesized that genetic variation in ABCB1 could influence postoperative seizure outcome in TLE patients. Design/Methods: We assembled 200 patients, who had undergone anterior temporal lobectomy (ATL) for AED-resistant TLE and had been followed up for 5 years after surgery. We genotyped seven SNPs in the ABCB1 gene using PCR-RFLP and compared the distribution of SNPs between patients who were seizure-free and those who had seizure recurrence. Results: Genotypic frequencies were in Hardy-Weinberg equilibrium with exception to rs1045642 in seizure-free group. There was no significant difference in allele and genotype frequencies of the SNPs in ABCB1 gene between patients who were seizure-free and those who had seizure recurrence. Conclusions: Even though studies have suggested that P-glycoprotein expression in temporal lobe may be associated with postoperative seizure recurrence, we could not find any association in genotypic level with the studied SNPs, so as to predict seizure recurrence. Supported by: BRNS and KSCSTE, Govt. of India. Disclosure: Dr. Balan has nothing to disclose. Dr. Sumitha has nothing to disclose. Dr. Bharadwaj has nothing to disclose. Dr. Lekshmi has nothing to disclose. Dr. Sathyan has nothing to disclose. Dr. Radhakrishnan has nothing to disclose. Dr. Banerjee has nothing to disclose.