Pathogenic variants in CHD2 (chromodomain helicase DNA-binding protein 2) have been reported in neurodevelopmental disorders with a broad spectrum of phenotypic variability, ranging from mild intellectual disability to atonic-myoclonic epilepsy.
In conclusion our study adds relevant features of the CHD2-epilepsy phenotype and confirms that CHD2 mutations produce a distinctive form of myoclonic epilepsy with visual-sensitive seizures.
The phenotypic spectrum of CHD2 encephalopathy has distinctive features of myoclonic epilepsy, marked clinical photosensitivity, atonic-myoclonic-absence, and intellectual disability ranging from mild to severe.