SLC6A5 and hereditary hyperekplexia: Mutations in the genes GLRA1 (GlyRα1), GLRB (GlyRβ), and SLC6A5 encoding GlyT2 are the major underlying causes of startle disease in humans and rodents (Rees et al., 2006; Chung et al., 2010, 2013; James et al., 2013; Bode and Lynch, 2014; Schaefer et al., 2015; Piro et al., 2021).