Novel de novo EEF1A2 missense mutations causing epilepsy and intellectual disability

Area of Science:

• Genetics
• Neurology
• Molecular Biology

Background:

• Exome sequencing identifies novel epilepsy genes, including EEF1A2.
• EEF1A2 mutations were previously found in severe epilepsy cases.
• This study investigates additional cases with EEF1A2 mutations.

Purpose of the Study:

• To identify and characterize new mutations in the EEF1A2 gene.
• To explore the phenotypic spectrum associated with EEF1A2 mutations.
• To determine the clinical significance of EEF1A2 in epilepsy and intellectual disability.

Main Methods:

• Case identification through the Deciphering Developmental Disabilities project and other clinical/online resources.
• Exome sequencing of affected individuals.
• Clinical evaluation and phenotypic analysis of new cases.

Main Results:

• Seven new cases with distinct EEF1A2 mutations were identified.
• Mutations cause epilepsy and intellectual disability across a broad severity spectrum.
• Shared subtle facial dysmorphic features were observed in new cases.
• Mutations affect highly conserved amino acid positions, suggesting functional importance.

Conclusions:

• EEF1A2 is implicated in epileptic encephalopathy and less severe epilepsy with intellectual disability.
• A recognizable phenotype, including specific facial features, may aid in identifying EEF1A2 mutation carriers.
• EEF1A2 should be considered in the genetic workup of epilepsy and intellectual disability.