Preliminary study about a significant and treatable cause of epileptic encephalopathy: GRIN2D mutation

Abstract

Aim: The GRIN2D gene mutation causes severe forms of epileptic encephalopathy. NMDAR antagonists and magnesium sulfate could be useful as adjunctive therapy to control seizures in individuals with GRIN2D encephalopathy. The aim of this study was to describe the clinical features and treatment options of GRIN2D encephalopathy. Methods: Patients followed up with epileptic encephalopathy in our pediatric neurology clinic were investigated for genetic etiology using next-generation sequencing (NGS)-based tests. Patients with the GRIN2D mutation were overviewed for clinical and genetic characteristics. Results: A total of 53 patients were screened and GRIN2D mutations (c.3684_3685insGA, c.3248_3254del, c.1579G>T, c.47_49del) were detected in four patients. Occipital epileptic activity was frequently detected among our patients. Three patients received memantine treatment for intractable epilepsy and remained seizure-free. Conclusion: GRIN2D encephalopathy is a treatable epileptic encephalopathy, and its recognition is important in terms of outcomes. Occipital epilepsy is generally benign, but developmental and epileptic encephalopathies such as GRIN2D encephalopathy should be considered in the presence of concomitant developmental delay.