Abstracts

Mesial temporal lobe epilepsy with hippocampal sclerosis is one of the most common medically intractable epilepsy syndromes and its pathogenesis remains obscure. The polymorphisms of single nucleotide (SNPs), alterations in a single nucleotide of DNA sequence, when non-synonymous, are capable of cause changes in protein[apos]s structure and have been studied in association studies. Recent studies demonstrated controversial results about the relationship between gene polymorphism and epilepsy. Several association studies involving more than 30 genes involved in Mesial Temporal Sclerosis (MTS) are described. However, it remains the uncertainty in associations and the imperfection in replications. The objective of this study is the molecular characterization of MTS., Thirty patients with MTS, well characterized by MRI, were pared by sex and age with 30 controls without family history of neurological or psychiatric disorders to be genotyped. The authors investigated, through search of new DNA SNPs, susceptibility genes to developmental of MTS. Initially, more than 100 genes coding to ionic channels and other genes related to neuronal migration and neurogenesis were evaluated. From these, 82 genes were selected. These genes were previously described in association studies of epilepsy or studies of families. To the moment, we found 20 non-synonymous polymorphisms in 11 different genes., In the initial experimental analysis, 14 SNPs find in 5 different genes were evaluated. The data show that for the first 30 patients, 8 SNPs were confirmed in 5 different genes ([italic]EFHC1, ME2, BRD2, BDNF [/italic]and[italic] TMEM1[/italic])., The number of patients and controls limited the statistical power of the ongoing study. Knowledge of these SNPs and their effect on genes involved with MTS may be important to help a better understanding of complexes pathways that characterize the neuronal hyperexcitability and the development of new strategies for treatment and diagnosis., (Supported by FAPESP 05/ 50135-3.)