[Clinical phenotype and genetic features of 16p11.2 microdeletion-related epilepsy in children].

Objectives: To study the clinical phenotype and genetic features of 16p11.2 microdeletion-related epilepsy in children.

Methods: The medical data of 200 children with epilepsy who underwent a genetic analysis of epilepsy by the whole exon sequencing technology were collected retrospectively, of whom 9 children with epilepsy had 16p11.2 microdeletion. The clinical phenotype and genetic features of the 9 children with 16p11.2 microdeletion were analyzed.

Results: The detection rate of 16p11.2 microdeletion was 4.5% (9/200). The 9 children with 16p11.2 microdeletion were 3-10 months old. They experienced focal motor seizures with consciousness disturbance, and some of the seizures developed into generalized tonic-clonic seizures. The interictal electroencephalogram showed focal or multifocal epileptiform discharge, and all 9 children responded well to antiepileptic drugs. The 9 children had a 16p11.2 deletion fragment size of 398-906 kb, and the number of deleted genes was 23-33 which were all pathogenic mutations. The mutation was of maternal origin in 2 children, of paternal origin in 1 child, and in the other children.

Conclusions: 16p11.2 microdeletion can be detected in some children with epilepsy. Most of the 16p11.2 microdeletion is mutation and large gene fragment deletion. The onset of 16p11.2 microdeletion-related epilepsy in children is mostly within 1 year of life, and the epilepsy is drug-responsive.