Clinical and Genetic Features in Patients With Reflex Bathing Epilepsy.

Abstract

To describe the clinical and genetic findings in a cohort of individuals with bathing epilepsy, a rare form of reflex epilepsy. We investigated by Sanger and targeted resequencing the <i>SYN1</i> gene in 12 individuals from 10 different families presenting with seizures triggered primarily by bathing or showering. An additional 12 individuals with hot-water epilepsy were also screened. In all families with bathing epilepsy, we identified 8 distinct pathogenic or likely pathogenic variants and 2 variants of unknown significance in <i>SYN1</i>, 9 of which are novel. Conversely, none of the individuals with hot-water epilepsy displayed <i>SYN1</i> variants. In mutated individuals, seizures were typically triggered by showering or bathing regardless of the water temperature. Additional triggers included fingernail clipping, haircutting, or watching someone take a shower. Unprovoked seizures and a variable degree of developmental delay were also common. Bathing epilepsy is genetically distinct reflex epilepsy caused mainly by <i>SYN1</i> mutations.