Eyelid myoclonia with absences, intellectual disability and attention deficit hyperactivity disorder: a clinical phenotype of the RORB gene mutation

Abstract

Eyelid myoclonia with absences is recently included in the category of childhood epileptic syndromes. It is clinically characterized by brief seizures of eyelid myoclonia, sometimes followed by absences, and it is associated to EEG generalized discharges of polyspikes or polyspike-waves, which are triggered by eyes closure in a well-lit room. This epileptic syndrome probably has a genetic origin, as well as other genetic generalized epilepsies, in particular photosensitive epilepsies. We describe the case of a patient affected by eyelid myoclonia with absences, intellectual disability, and attention deficit hyperactivity disorder (ADHD), with a de novo mutation of the RORB gene (retinoid-related orphan receptor β); this gene is involved in vivo in different neuronal processes among which are migration and differentiation. We suggest that its mutation in our patient can be considered the cause of the aberrant functioning of the cerebral cortex, which is clinically expressed by epilepsy and neurodevelopment disorders.

Keywords: Eyelid myoclonia with absences; Intellectual disability; Photosensitivity; RORB gene.