Introduction: Epilepsy is a common neurological disorder affecting approximately 1% of
the global population. A significant proportion of patients develop drug-resistant epilepsy
(DRE), which leads to poor outcomes for treatments and low quality of life. The multidrug
transporter P-glycoprotein, encoded by the ABCB1 gene, plays a key role in limiting brain
penetration of antiepileptic drugs. The C3435T single nucleotide polymorphism (SNP) in
ABCB1 has been linked to variable P-glycoprotein expression and AED response. In this
study, the prevalence of C3435T genotypes among epilepsy patients and healthy controls in
Fars Province, Iran was investigated.
Materials and methods: This study involved 50 patients diagnosed with epilepsy and 100
healthy individuals without a history of seizures or epilepsy. Genotyping was conducted
using PCR-RFLP analysis.
Results: The variant T allele occurred at a frequency of 52% in cases and 54% in controls.
However, no significant association between the C3435T polymorphism and epilepsy risk
was observed. Interestingly, it was found that the CT genotype was overrepresented in
drug-responsive patients compared to those with drug-resistant cases. This suggests that
individuals with the CT genotype may have a more favorable response to antiepileptic drug
Conclusion: These findings suggest that the ABCB1 C3435T variant may play a role
in influencing seizure control specifically among Iranian patients, but its effects on
susceptibility are minimal. Moreover, individuals with the CT genotype may have a more
favorable response to antiepileptic drug therapy. Further research involving larger cohorts
is needed to fully understand the impact of ABCB1 genetics on determining individual
responses to antiepileptic drugs. Such research could also pave the way for personalized
management strategies based on pharmacogenomic testing.
epilepsy, ABCB1 C3435T, gene polymorphism, P-glycoprotein