GRIN2D-related neurodevelopmental disorder is characterized by DD/ID, muscular hypotonia, epilepsy and movement disorder. Individuals with GRIN2D-related neurodevelopmental disorder have been reported less frequently than individuals with other GRIN-related disorders. All affected individuals known so far have moderate-to-severe DD/ID. Epilepsy is seen in nearly all affected individuals showing severe, early-onset, medically refractory epileptic encephalopathy (including spasms with hypsarrhythmia). Additional features are muscular hypotonia, spasticity, feeding difficulties and movement disorders. GRIN2D-related neurodevelopmental disorder is inherited in an autosomal dominant manner. All individuals reported to date with a GRIN2D-related neurodevelopmental disorder whose parents have undergone molecular genetic testing have the disorder as a result of a de novo GRIN2D pathogenic variant.
GRIN2D