Abstracts

Rationale: There is a growing interest in molecular mechanisms of epilepsy. Brain-Derived Neurotrophic Factor (BDNF) is a protein directly involved in neuronal development and protection, besides synaptic functioning. Changes in production and function of this protein may affect epileptogenesis. Impact of the recently described Val66Met polymorphism of BDNF gene in epileptic disorders has been published, with conflicting results. In this study, we compare frequencies of Val66Met polymorphism in two different groups of subjects, patients with temporal lobe epilepsy and normal controls. Also, we accessed its possible impact on major clinical variables of temporal lobe epilepsy. Methods: In a case-control study, we compare the frequencies of Val66Met polymorphism in 85 patients with temporal lobe epilepsy to 87 normal controls. All subjects in study were Caucasians, and there were no statistical differences between groups regarding mean age and gender. In a second step, we studied separately the patients group, evaluating clinical variables related to the epileptogenic process. Results: The Val66Met polymorphism frequency in epileptic patients was not different from the normal controls (p = 0.25). Met66 allele was found in 23 patients (27.1%) and in 30 controls (34.5%). Moreover, the Val66Met polymorphism did not influence clinical variables regarding gender, age of onset of epilepsy, duration of epilepsy, control of seizures, familial history of epilepsy, presence of aura, or extension of irritative zone. Conclusions: In spite of abundant evidences that Val66Met BDNF polymorphism has impact on several different neurological or psychiatric disorders we conclude that a direct impact of Val66Met polymorphism as a disease modifier in temporal lobe epilepsy is unlikely. However, because of the impact of this polymorphism in several other pathologies and several evidences from preclinical studies relating BDNF with epilepsy, further studies with larger samples evaluating possible marginal influences of BDNF polymorphisms in TLE are still needed before final conclusions can be reached.