Previous studies have attributed dominant forms of hyperekplexia 1 to mutations within the pore-lining transmembrane segment (TM2) and adjacent regions, recessive forms to mutations within the other transmembrane segments (TM1 and TM3), and the null allele of the GLRA1 gene to the deletion of exons 1-7 [11,12]. Here, GLRA1 is linked to hereditary hyperekplexia.