Higher transcription alleles of the MAOA-uVNTR polymorphism are associated with higher seizure frequency in temporal lobe epilepsy.

Background: There is evidence of an imbalance in the neuromodulatory system mediated by serotonin (5-HT) in patients with drug-resistant temporal lobe epilepsy (TLE). This study analyzed the monoamine oxidase A promoter variable number of tandem repeats (MAOA-uVNTR) polymorphism in patients with temporal lobe epilepsy with hippocampal sclerosis (TLE-HS). Therefore, we assessed the association between this genetic variant and seizure predisposition and severity in patients with TLE-HS.

Methods: One hundred nineteen patients with TLE-HS and 113 healthy volunteers were assessed. First, we genotyped all individuals for the MAOA-uVNTR genetic polymorphism. Second, we compared patients and controls and evaluated clinical variants of epilepsy.

Results: There was no difference between the TLE-HS and control groups regarding genotypic and allelic distributions of MAOA-uVNTR polymorphism (p = 1.000). Higher transcription alleles of the MAOA-uVNTR were associated with higher seizure frequency (p = 0.032) and bilateral tonic-clonic seizures (p = 0.016).

Conclusions: In a selected group of patients with TLE-HS, the polymorphism MAOA-uVNTR was associated with some aspects of epilepsy severity, namely seizure frequency and bilateral tonic-clonic seizures.