Autism, Electrical Status Epilepticus in Sleep, and a Likely Pathogenic SEMA6B Variant

This case report describes a boy aged 8 years with autism spectrum disorder who was diagnosed with electrical status epilepticus in sleep (ESES) and found to have a likely pathogenic variant in the SEMA6B gene. The patient presented with developmental regression and cognitive decline. An electroencephalogram demonstrated continuous spike-and-wave discharges during sleep, a hallmark of ESES. Genetic testing identified a De Novo likely pathogenic variant in SEMA6B, a gene implicated in neurodevelopmental disorders and epilepsy. Although the association between SEMA6B mutations and ESES is not well established, this case suggests that the genetic variant may have contributed to the patient's clinical presentation. This is the first reported instance of ESES being linked to a SEMA6B gene variant, highlighting the importance of genetic testing in similar cases. The findings could have significant implications for the understanding and management of ESES in autistic patients with behavioral difficulties. They also underscore the need for further research into the role of SEMA6B in epilepsy and neurodevelopmental disorders.