Epilepsy due to a MED25 Homozygous Pathogenic Founder Variant

Area of Science:

• Genetics
• Neurology
• Pediatrics

Background:

• MED25 pathogenic variants are associated with diverse clinical phenotypes.
• Basel-Vanagaite-Smirin-Yosef syndrome is a rare autosomal recessive disorder with varied symptoms, including epilepsy.
• The electroclinical characteristics of epilepsy in this syndrome remain poorly documented.

Purpose of the Study:

• To describe the detailed electroclinical phenotypes of epilepsy in patients with Basel-Vanagaite-Smirin-Yosef syndrome.
• To report on three patients from two Lebanese families with a homozygous MED25 founder variant.

Main Methods:

• Clinical case series reporting on three affected individuals.
• Detailed description of electroencephalogram (EEG) findings, including seizure types and discharge patterns.
• Review of existing literature on Basel-Vanagaite-Smirin-Yosef syndrome and epilepsy.

Main Results:

• Patients presented with seizures starting between 2 and 3 years of age.
• EEG revealed multifocal and generalized epileptiform discharges.
• Photoparoxysmal responses were observed on electroencephalogram in these patients.

Conclusions:

• The study characterizes specific electroclinical epilepsy phenotypes in Basel-Vanagaite-Smirin-Yosef syndrome.
• Findings contribute to a better understanding of seizure characteristics associated with MED25 variants.
• Highlights the importance of detailed electroclinical evaluation in rare genetic epilepsy syndromes.