Genetic Landscape of Photoparoxysmal Response in Epilepsy.

Photoparoxysmal response (PPR), often observed in epilepsy, is an abnormal cortical response to photic stimulation manifesting as specific EEG changes. It is a highly heritable EEG trait. Here, the authors have done a whole-exome sequencing (WES) study of epilepsy patients with PPR in a south Indian cohort, in an attempt to identify the genetic causes of epilepsy with PPR. The study design was prospective, exploratory and descriptive. Twenty-eight patients with idiopathic epilepsy, exhibiting Grade 4 PPR, were recruited for the study. Variants identified as likely pathogenic and those categorized as variants of uncertain significance were detected in genes associated with epilepsy, as well as in genes implicated in syndromes associated with epilepsy. This is the first comprehensive genetic study of PPR in an Indian population.