Introduction: Developmental and epileptic encephalopathy (DEE) constitute an heterogeneous group of age-related severe epileptic syndromes, of predominantly genetic origin. The development of next generation-sequencing (NGS) techniques has shortened the diagnostic pathway. Objective: Our aim was to study the clinical, electrophysiological and radiological features of DEEs in a Tunisian pediatric population. Methods: It is a retrospective and descriptive study conducted between 2005 and 2023 in the Child and Adolescent Neurology Department at the Institut National Mongi Ben Hmida of Neurology, Tunisia. Results: Twenty-four cases (8 girls/16 boys) were included. The mean age of onset was 12.32 months [40 days, 8 years], with neonatal onset observed in 7 cases. the seizures were, in the majority of cases focal motor seizures (n=10). General exam showed movements disorders (n=9), intellectual impairment with autistic features (n=6), dysmorphic features (n=6), strabismus (n=6), skeletal abnormality (n=4), ataxia (n=3), microcephaly (n=3), hearing loss (n=1). EEG showed focal abnormalities (n=10), generalized abnormalities (n=10), slow background (n=8), a disorganized background (n=2), migrating ictal discharges (n=2), suppression Burst (n=1) and hypsarrhythmia (n =1). Brain MRI showed atrophy of the corpus callosum (n=3), cerebral atrophy (n=4) and mesial sclerosis (n=1). Genes identified in our series were SCN1A(8), KCNQ2(3), CTCF(2), FRRS1L(2), PCDH19(1), KCNT1(1), ATP1A3(1), STXP1(1), CDKL5(1), GRIN1(1), FGF12(1),PIGM(1), SLC25A12(1). Conclusion: Our study highlights the heterogeneity of DEE and the importance of genetic screening. Advances in genetic research are transforming knowledge in terms of classifications, syndromic diagnosis and treatment in the field of epilepsy.

Cyrine Karray
National institute of Neurology Mongi Ben Hmida
Tunisia

Zouhour Miladi
National institute of Neurology Mongi Ben Hmida
Tunisia

Thouraya Ben Younes
National institute of Neurology Mongi Ben Hmida
Tunisia

hedia klaa
National institute of Neurology Mongi Ben Hmida
Tunisia

abir zyoudi
National institute of Neurology Mongi Ben Hmida
Tunisia

Ichraf Kraoua
National institute of Neurology Mongi Ben Hmida
Tunisia

Hanen Ben Rhouma
National institute of Neurology Mongi Ben Hmida
Tunisia

ilhem ben youssef turki
National institute of Neurology Mongi Ben Hmida
Tunisia