Clinical and genetic investigation of 17 Japanese patients with hyperekplexia. (30th October 2014)

• Record Type: Journal Article
• Authors: Mine, Jun; Taketani, Takeshi; Yoshida, Kazushi; Yokochi, Fusako; Kobayashi, Junpei; Maruyama, Koichi; Nanishi, Etsuro; Ono, Mayumi; Yokoyama, Atsushi; Arai, Hidee; Tamaura, Shiho; Suzuki, Yasuhiro; Otsubo, Shusuke; Hayashi, Takashi; Kimura, Masahiko; Kishi, Kazuko; Yamaguchi, Seiji
• Is Part Of: Developmental medicine & child neurology. Volume 57:Number 4(2015:Apr.)
• Page Start: 372
• Page End: 377
• Publication Date: 2014-10-30
• Subjects: Child development -- Periodicals; Pediatric neurology -- Periodicals; 616.8
• DOI: 10.1111/dmcn.12617
• Languages: English
• ISSNs: 0012-1622

Abstract

<abstract abstract-type="main" id="dmcn12617-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="dmcn12617-sec-0001" sec-type="section"> <title>Aim</title> <p>The aim of the study was to determine clinical and genetic characteristics of Japanese patients with hyperekplexia.</p> </sec> <sec id="dmcn12617-sec-0002" sec-type="section"> <title>Method</title> <p>Clinical courses, responses to antiepileptic drugs, outcomes, and genetic testing were investigated in 17 Japanese patients (nine males, eight females, median age 1y, range birth–45y) with hyperekplexia.</p> </sec> <sec id="dmcn12617-sec-0003" sec-type="section"> <title>Results</title> <p>In all patients, muscle stiffness and startle responses appeared soon after birth. Only seven patients were diagnosed with hyperekplexia before 1 year of age. Seven patients had been misdiagnosed with other disorders such as epilepsy and adult‐onset anxiety neurosis. Umbilical/inguinal hernias were seen in 10 patients. Life‐threatening events were noted in four patients. Clonazepam was the most effective drug. Muscle stiffness completely disappeared in 12 patients before 5 years of age, whereas startle responses resolved in only three patients. Mutations in the <italic>GLRA1</italic> and <italic>GLRB</italic> genes were identified in 16 patients and one patient respectively. In 14 patients, the mutation showed autosomal dominant inheritance; in the other three, inheritance was autosomal recessive. p.R271Q of <italic>GLRA1</italic> was the most frequent mutation, found in 10 patients. Novel mutations, p.A272P and p.A384P of <italic>GLRA1</italic>, were detected. Clinical severity and outcome varied even in the same family.</p> </sec> <sec id="dmcn12617-sec-0004" sec-type="section"> <title>Interpretation</title> <p>Early correct diagnosis is essential for prevention of accidental injuries and to provide appropriate treatments for hyperekplexia. Clonazepam is effective, although the time taken for startle responses to resolve varied.</p> </sec> </abstract>