GLRA1 and hyperekplexia: Hyperekplexia (HK) is an infrequent neurological disorder characterized by excessive startle responses noticed shortly after birth.1,2 It is a form of startle syndrome and can be divided into three main subgroups: hereditary, sporadic, and symptomatic.3 The genetic mutation in patients with this disease is often found in the α1 subunit of the glycine receptor, GLRA1.4 In addition to the GLRA1 gene, SLC6A5, GLRB, GPHN, and ARHGEF9 gene mutations have also been described.5,6 More than 200 confirmed cases have been reported worldwide.7