title: Clinical features and genetic analysis of children with hyperekplexia in Korea.
abstract: Hyperekplexia is a rare inherited neurologic disorder that is characterized by hypertonia and an exaggerated startle response to sudden external stimuli. Until now, 5 genes are known to be associated with hyperekplexia: GLRA1, SLC6A5, GLRB, GPHN, and ARHGEF9. In this report, we performed a clinical and genetic analysis of 4 Korean children with hyperekplexia. Two patients had typical clinical manifestations of hyperekplexia that initially were misdiagnosed as epilepsy. Direct sequencing of the GLRB and GLRA1 genes revealed 2 novel mutations, GLRB c.298-1G>A and c.1028C>T (p.S343F), in patient 1 and 1 novel mutation, GLRA1 c.895C>T (p.R299X), in patient 2. The other 2 familial cases, patients 3 and 4, exhibited startle responses, which appeared at the age of 1 year, and had global developmental delay. Those patients showed negative results for the 5 genes.
authors.affiliation: Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cha Gon
authors.initials: CG
authors.lastname: Lee
authors.forename: Min-Jung
authors.initials: MJ
authors.lastname: Kwon
authors.forename: Hee Joon
authors.initials: HJ
authors.lastname: Yu
authors.forename: Sook Hyun
authors.initials: SH
authors.lastname: Nam
authors.forename: Jeehun
authors.initials: J
authors.lastname: Lee
authors.forename: Chang-Seok
authors.initials: CS
authors.lastname: Ki
authors.forename: Munhyang
authors.initials: M
authors.lastname: Lee
mesh_terms: D002352:Carrier Proteins / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D004827:Epilepsy / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D040181:Genetic Diseases, X-Linked / Q000453:epidemiology / Q000235:genetics*; D050487:Glycine Plasma Membrane Transport Proteins / Q000235:genetics*; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D018009:Receptors, Glycine / Q000235:genetics*; D012021:Reflex, Abnormal / Q000235:genetics*; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D064067:Rho Guanine Nucleotide Exchange Factors; D012720:Severity of Illness Index
chemical_list: C577410:ARHGEF9 protein, human; D002352:Carrier Proteins; C000657604:GLRA1 protein, human; C114561:GLRB protein, human; D050487:Glycine Plasma Membrane Transport Proteins; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; D018009:Receptors, Glycine; D064067:Rho Guanine Nucleotide Exchange Factors; C493271:SLC6A5 protein, human; C073441:gephyrin