De Novo and Inherited SETD1A Variants in Early-onset Epilepsy

Early-onset epilepsy is a neurological abnormality in childhood, and it is especially common in the first2 years after birth. Seizures in early life mostly result from structural or metabolic disorders in the brain, and the genetic causes of idiopathic seizures have been extensively investigated. In this study, we identified four missense mutations in the SETD1 A gene(SET domain-containing 1 A, histone lysine methyltransferase): three de novo mutations in three individuals and one inherited mutation in a four-generation family. Whole-exome sequencing indicated that all four of these mutations were responsible for the seizures. Mutations of SETD1 A have been implicated in schizophrenia and developmental disorders, so we examined the role of the four mutations(R913 C, Q269 R, G1369 R, and R1392 H) in neural development. We found that their expression in mouse primary cortical neurons affected excitatory synapse development. Moreover, expression of the R913 C mutation also affected the migration of cortical neurons in the mouse brain.We further identified two common genes(Neurl4 and Usp39) affected by mutations of SETD1 A. These results suggested that the mutations of SETD1 A play a fundamental role in abnormal synaptic function and the development of neurons, so they may be pathogenic factors for neurodevelopmental disorders.

Identification of the Genetic Cause for Childhood Disintegrative Disorder by Whole-Exome Sequencing

Dear Editor,Childhood Disintegrative Disorder（CDD）,also known as Heller’s syndrome and disintegrative psychosis,is a rare progressive neurological disorder,characterized by a late onset（[2 years of age）and regression of language,social