GRIN2B-related neurodevelopmental disorder

GRIN2B-related neurodevelopmental disorder is a rare neurodevelopmental disorder which is characterized by developmental delays and intellectual disabilities of variable degrees, muscle tone anomalies, feeding difficulties, and behavioral problems.

Signs and symptoms
The following list comprises most of the symptoms people with GRIN2B show:
 * Intellectual disability (mild to severe)
 * Developmental delay (mild to severe)
 * Hypotonia
 * Epilepsy
 * Autism spectrum disorder
 * Autistic-like behavior
 * Microcephaly
 * Hyperactivity
 * Stereotypy
 * Spasticity
 * Feeding difficulties

Less common symptoms include:
 * Visual impairment
 * Dystonia
 * Dyskinesia
 * Other choreiform movement disorder

Causes
This condition is caused by mutations in the GRIN2B gene, located in chromosome 12.

This gene makes instructions into how to make a protein called GluN2B, a type of NMDA receptor, which is found in brain neurons during ante-natal brain development. It is involved in correct brain development and function, regulating memory, synaptic plasticity and the ability of learning.

Epidemiology
Around 100 cases have been described in medical literature.