A case of early-onset epileptic encephalopathy in infant with Autosomal recessive GRIN1 related neurodevelopmental disorder caused by homozygous nonsense variant

Abstract

Glutamate receptor, ionotropic,NMDA-1(GRIN1)geneencodesGluN1 subunit of NMDA receptor. Pathogenic variants cause an autosomal dominant or recessive neurodevelopmental disorder (ADorARGRIN1-NDD).Although the reported cases to date less than 100 individuals, most of them ADGRIN1-NDD, only nine were described as ARGRIN1-NDD. Here were porta homozygous variantin GRIN1in a4- month-old boy with early infantile epilepticence phalopathy. As suggested by literature, individuals carrying homozygous nonsense variants exhibit more severe phenotype, which could be explained by complete splicing disruptionofGRNI1 transcription.