EPILEPSY IN CYTOGENETIC ABNORMALITIES: PREVALENCE, PHENOTYPE CLASSIFICATION, AND PROGNOSTIC FACTORS

Background: Many chromosomal abnormalities are associated with Central Nervous System (CNS) malformations and other neurological alterations, among which seizures and epilepsy. Certain chromosomal syndromes are specifically associated with epilepsy and show a particular clinical and EEG pattern. This retrospective research proposal will study the prevalence of epilepsy in cytogenetic abnormalities, its classification and the prognostic factors regarding the response to Anti-epileptic medications (AED). Objective: The present study aims at exploring prevalence of epilepsy in cytogenetic abnormalities, its classification and Prognostic factors of responsiveness to anti-epileptic medication. Design and Setting: a retrospective study that was carried out in Prince Sultan Military Medical City, Riyadh, Saudi Arabia, that included a review of all chromosomal abnormalities (2010-2018). The chromosomal abnormalities were detected by chromosomal study, FISH, or array CGH . All patients with chromosomal abnormalities who develop epilepsy were included. Detailed clinical assessment was done through recording seizures, EEG, and MRI brain finding. Statistical analysis: Data were represented in terms of frequencies and valid percentages for categorical variables. The analysis was done using SPSS version 26. Results: 550 patients were included in this study. The prevalence of seizures in the whole cohort was 14.7%, with 45.7% of females and 54.3% of males having seizures. Additionally, 44.4% of the whole cohort had a chromosomal micro-deletion abnormality, followed by 23.5% with chromosomal micro-duplication. As for the age of onset, 48% of patients with seizures had their first seizure at the age of less than one-year-old. 52.5% of the patients had generalized seizures followed by focal epilepsy in 29.4% of patients. 41.1% of patients with seizures showed unremarkable findings on Brain MRI, and congenital brain malformations in different chromosomal aberrations 27.6 % and 11.1% had a Lennox-Gastaut syndrome (LGS) after treatment Conclusion: Epilepsy in patients with cytogenetic abnormalities appears to have a higher incidence in Saudi Arabia compared to western countries. Genetic deletions and duplications are the most common predictive factors for the occurrence of epilepsy