Infantile spasm, an unreported epilepsy form of CHD3 gene: A case report

CHD3 protein encoded by the CHD3 gene belongs to the second subfamily of the CHD family. The protein highly demonstrates in brain and is mostly in the developmental cortex. Its function is to promote the formation of late neural migration and cortex. Previously, CHD3 gene variants causing epilepsy are rare and only 1 case has been reported. The variation is a missense variant located at the C-terminal end of the deconvolution enzyme. However, there are no CHD3 gene mutations that have been reported to cause infantile spasms (IS) as yet. In the present study, we perform whole-exome sequencing (WES) in a patient of IS with neurodevelopmental disorders. This study suggests that CHD3 is potentially a candidate causative gene of IS.

Children was admitted to our hospital for a detailed evaluation of frequent seizures. Children have abnormal electroencephalogram and brain magnetic resonance imaging results, accompanied by developmental delay.

A genetic study using trio-WES confirmed the diagnosis of CHD3-related IS.

Patient accepted the treatment of antiepileptic drugs. One patient had seizure remission with a combination of adrenocorticotropin and topiramate.

Whole-exome sequencing technology was used to determine the etiology of the children with IS. The patient had gained seizure-free, and the follow-up electroencephalography discharges were reduced.

This study confirmed that genetic testing provides a basis for the diagnosis of children with abnormal electroencephalogram and brain magnetic resonance imaging findings and developmental delay, and provides data supporting a future phenotype genotype correlation study. The CHD3 gene may be a new gene for IS, and the possibility of carrying a CHD3 gene variation should also be considered in children who present only with neurodevelopmental disorder without seizures.