A rare genetic neurological disorder characterized by neonatal onset of rigidity and intractable seizures, with episodic jerking already beginning in utero. Affected infants have small heads, remain visually inattentive, do not feed independently, and make no developmental progress. Frequent spontaneous apnea and bradycardia usually culminate in cardiopulmonary arrest and death in infancy, although some cases were described with a milder clinical course and survival into childhood. The cause of the disease is a variation in the BRAT1 gene. The disease is Monarch Disease Ontology identifier MONDO_0013784 (neonatal-onset encephalopathy with rigidity and seizures). Also known as: lethal neonatal rigidity-multifocal seizure syndrome, lethal neonatal spasticity-epileptic encephalopathy syndrome.