GRIN2B-related neurodevelopmental disorder

GRIN2B-related neurodevelopmental disorder is a rare neurodevelopmental disorder that is characterized by developmental delays and intellectual disabilities of variable degrees, muscle tone anomalies, feeding difficulties, and behavioral problems.^[1]

GRIN2B-related neurodevelopmental disorder
Other names	GRIM2B-associated disorder
Specialty	Medical genetics, Pediatry, Neurology
Symptoms	Mainly developmental delays, intellectual disabilities, craniofacial dysmorphisms, behavioural problems and muscle tone anomalies
Complications	Learning disability, communication delay, social ineption
Usual onset	Birth
Duration	Lifelong
Causes	Genetic mutation
Diagnostic method	Genetic testing and physical examination
Prevention	None
Prognosis	Medium
Frequency	Rare, only 100 cases have been described in medical literature
Deaths	-

Signs and symptoms

The following list comprises most of the symptoms people with GRIN2B show:^[2][3]

• 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:^[4]

• Visual impairment
• Dystonia
• Dyskinesia
• Other choreiform movement disorder

Causes

This condition is caused by mutations in the GRIN2B gene, located in chromosome 12.^[5]

This gene instructs 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.^[6]

Epidemiology

Around 100 cases have been described in medical literature.^[7]