Akihisa Okumura1, Keiko Shimojima2, Hirokazu Kurahashi3, Shingo Numoto3, Shino Shimada2, Atsushi Ishii4, Iori Ohmori5, Satoru Takahashi6, Tomonari Awaya7, Tetsuo Kubota8, Takafumi Sakakibara9, Naoko Ishihara10, Ayako Hattori11, Hiroyuki Torisu12, Jun Tohyama13, Takeshi Inoue14, Akiko Haibara15, Takuji Nishida16, Yukihiro Yuhara17, Kazushi Miya18, Ryuta Tanaka19, Shinichi Hirose4, Toshiyuki Yamamoto2. 1. Department of Pediatrics, Aichi Medical University, Japan. Electronic address: okumura.akihisa.479@mail.aichi-med-u.ac.jp. 2. Institute of Medical Genetics, Tokyo Women's Medical University, Japan. 3. Department of Pediatrics, Aichi Medical University, Japan. 4. Department of Pediatrics, Fukuoka University School of Medicine, Japan. 5. Department of Physiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan. 6. Department of Pediatrics, Asahikawa Medical University, Japan. 7. Department of Pediatrics, Kyoto University Graduate School of Medicine, Japan. 8. Department of Pediatrics, Anjo Kosei Hospital, Japan. 9. Department of Pediatrics, Nara Medical University, Japan. 10. Department of Pediatrics, Fujita Health University School of Medicine, Japan. 11. Department of Pediatrics and Neonatology, Nagoya City University Graduate School of Medical Sciences, Japan. 12. Section of Pediatrics, Department of Medicine, Fukuoka Dental College, Japan. 13. Department of Pediatrics Epilepsy Center, Nishi-Niigata Chuo National Hospital, Japan. 14. Department of Pediatric Neurology, Osaka City General Hospital, Japan. 15. Department of Pediatrics, Tsuchiura Kyodo General Hospital, Japan. 16. National Epilepsy Center, Shizuoka Institute of Epilepsy and Neurological Disorders, NHO, Japan. 17. Department of Pediatrics, NHO Numata Hospital, Japan. 18. Department of Pediatrics, University of Toyama, Faculty of Medicine and Pharmaceutical Sciences, Japan. 19. Department of Child Health, University of Tsukuba, Faculty of Medicine, Japan.
Abstract
PURPOSE: This study was performed to clarify the clinical features of Japanese patients with PRRT2 mutations. METHODS: The PRRT2 gene was analyzed in 135 patients with benign infantile epilepsy (BIE) or paroxysmal kinesigenic dyskinesia (PKD) using a direct sequencing method: 92 patients had BIE alone, 25 had both BIE and PKD, and 18 had PKD alone. Of the cases, 105 were familial, and 30 were sporadic. Clinical information was collected using a structured questionnaire. RESULTS: PRRT2 mutations were identified in 104 patients. Among the familial cases, PRRT2 mutations were found in at least one individual in 21 of 28 families with BIE alone, in 26 of 27 families with infantile convulsions and choreoathetosis, and in 2 of 3 families with PKD alone. Among the sporadic cases, PRRT2 mutations were observed in 7 of 25 patients with BIE alone, in 1 of 1 patient with BIE and PKD, and in 3 of 4 patients with PKD alone. The c.649dupC mutation was the most frequent, followed by the c.981C > G mutation. Among the patients with epilepsy, the median age at BIE onset was 5 months, the median age at the last seizure was 6 months, and the median number of seizures was 5. CONCLUSION: PRRT2 mutations were found in 68% of Japanese probands with BIE or PKD. The phenotypes of BIE associated with PRRT2 mutations were consistent with those of BIE diagnosed clinically.
PURPOSE: This study was performed to clarify the clinical features of Japanese patients with PRRT2 mutations. METHODS: The PRRT2 gene was analyzed in 135 patients with benign infantile epilepsy (BIE) or paroxysmal kinesigenic dyskinesia (PKD) using a direct sequencing method: 92 patients had BIE alone, 25 had both BIE and PKD, and 18 had PKD alone. Of the cases, 105 were familial, and 30 were sporadic. Clinical information was collected using a structured questionnaire. RESULTS:PRRT2 mutations were identified in 104 patients. Among the familial cases, PRRT2 mutations were found in at least one individual in 21 of 28 families with BIE alone, in 26 of 27 families with infantile convulsions and choreoathetosis, and in 2 of 3 families with PKD alone. Among the sporadic cases, PRRT2 mutations were observed in 7 of 25 patients with BIE alone, in 1 of 1 patient with BIE and PKD, and in 3 of 4 patients with PKD alone. The c.649dupC mutation was the most frequent, followed by the c.981C > G mutation. Among the patients with epilepsy, the median age at BIE onset was 5 months, the median age at the last seizure was 6 months, and the median number of seizures was 5. CONCLUSION:PRRT2 mutations were found in 68% of Japanese probands with BIE or PKD. The phenotypes of BIE associated with PRRT2 mutations were consistent with those of BIE diagnosed clinically.