Biallelic mutations in valyl-tRNA synthetase gene VARS are associated with a progressive neurodevelopmental epileptic encephalopathy

Valyl-tRNA synthetase (VARS) charges valyl-tRNA with the amino acid valine, required for translation. Here, the authors describe a progressive epileptic encephalopathy in individuals from five families carrying biallelic mutations in the VARS gene that leave the enzyme activity partially intact.