Detection of mutation frequencies in idiopathic epilepsy patients by next generation sequencing

Epilepsy is a chronic case and disorder that occurs with the repetition of unprovoked seizures, with electrical discharges and abnormalities occurring in cortical neurons. An epileptic seizure is a situtaion of "temporary manifestation of signs and/or symptoms resulting from abnormal excessive or synchronous neuronal activity in the brain". According to the latest data of the World Health Organization, 65 million people have been diagnosed with epilepsy and between 70.000 and 128.00 new cases are added to the literature annually. The aim of this study is to evaluate the reflection of the clinical finding and mutation correlation of the patients on the patient's clinical feature. Furthermore, To demonstrate clinical heterogeneity among patients with the same mutation but with a different clinical course. In this study, clinical parameters including EEG, seizure type and frequency, and antiepileptic drugs and the behavioral characteristics of the patients were evaluated together with the mutations using the NGS method. Mutations detected in a total of 23 patients followed up with the diagnosis of idiopathic epilepsy; in 2 patients, heterozygous SCN1A c.264+3G>A mutation; heterozygous CHRNA2 c.402G>C (p.Arg134Ser) mutation in 1 patient; heterozygous CACNA1 c.1438C>T (p.Arg480Cys), c.6974_6976dupAGG (p.Gln2325_Ala232insGlu), c.3410C>G (p. Pro1137Arg) mutations in 3 patients, respectively; SCN3A heterozygous c.654C>G (p.Phe218Leu) mutation in 1 patient; heterozygous SLC2A1 (p.Gln200His) mutation in 1 patient; KCNMA1 heterozygous c.364G>A (p.Gly122Arg) mutation in 1 patient; heterozygous KCNMB3 c.192C>G (p.Leu64=) mutation in 1 patient; BRD2 heterozygous c.145_146delGCinsTG (p.Ala49Cys) in 1 patient; EFHC1 heterozygous c.1504C>T (p.Arg483Trp) in 1 patient; TBC1D24 heterozygous c.74A>G in 1 patient; Homozygous GRIN2A c.1265T>C (p.Ile422Thr) mutation was detected in 1 patient and TBC1D221 heterozygous c.1057G>A (p.Ala353Thr) mutation was detected in 1 patient, and no pathogenic variant was detected in 11 patients. As a result of this study, patients with the same mutational change were followed up with different clinical features and treatment; Different mutational changes, polymorphisms, epigenetic factors, environmental factors that could not be determined in this study on the genome may cause differences in clinical and post-treatment status. In conclusion, this study has revealed the clinical and mutational heterogeneity among the patients and will be able to illuminate the pathogenesis of many epileptic seizures and classified epilepsy types, especially within the scope of investigating molecular pathways in which genes are expressed.