GLRB and hyperekplexia: By contrast, GLRB mutations are less frequent, but recessive mutations have been discovered in three families with hyperekplexia (Al-Owain et al., 2012; Lee et al., 2012; Rees et al., 2002), in the mouse mutant spastic (Kingsmore et al., 1994; Mülhardt et al., 1994) and the zebrafish bandoneon mutant (Hirata et al., 2005).