Investigation of the Relationship Between Clinical and EEG Findings of Photosensitive Epilepsy and GABA Receptor Alpha 1 Subunit (GABRA1) Gene Mutations

Objective: Although photosensitive epilepsy (PE) is commonly observed, its pathophysiology has not been clarified yet. However, relevant literature indicates that genetic factors play an important role. Our aim was to investigate whether there is a relationship between the clinical and electroencephalographic (EEG) features and the possible mutations/polymorphisms in the GABA receptor alpha 1 subunit (GABRA1) gene in patients with PE by scanning this gene. Methods: 54 patients diagnosed as having PE according to International League Against Epilepsy (ILAE) criteria were included in the study. The patients were analyzed in terms of gender, clinical and syndromic features, response to treatment, EEG features, and photoparoxysmal response (PPR) types. Mutation screening was done by denaturing high-performance liquid chromatography (DHPLC) on all exons belonging to GABRA1 gene. Results: We could not detect any mutation in GABRA1 gene in patients with PE. Four single-nucleotide polymorphisms (SNPs) in GABRA1 gene were observed, but none of them were associated with amino acid changes. Besides, when comparing the patients having these SNPs with the remaining patients without any SNPs in regard to clinical and EEG features, we were not able to find a statistically significant difference for GABRA1 gene. Conclusion: The lack of mutations in the GABRA1 gene indicates that this gene is not predominantly involved in the etiopathogenesis of PE in the Turkish population. In order to get more precise evidence, the research should be extended by increasing the number of patients and by investigating other genes related to GABA. (Archives of Neuropsychiatry 2011; 48: 39-43)