パーソナルゲノム解析によるてんかんの分子生物学的発症機序の解明

2013 Fiscal Year Annual Research Report

• Project Area: Personal genome-based initiatives toward understanding bran diseases
• Project/Area Number: 25129708
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Research Institution: Fukuoka University
• Principal Investigator: 廣瀬 伸一 福岡大学, 医学部, 教授 (60248515)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: てんかん / 遺伝子変異 / エクソーム / 次世代シークエンサー

Research Abstract

てんかんはあまりに多様であるため、分子生物学的成因はほとんど不明であった。しかしながら、最近の分子生物学の進歩により、遺伝子異常が見いだされるようになった。特に最近の1～2年では次世代シークエンサーの登場により、次々と遺伝子変異が様々な遺伝子に発見されるようになった。一方で、すでに遺伝子異常が知られている病型でもその遺伝子が見いだされるのはごく一部で、表現型は同一でも多様な遺伝子異常が関係していることが予想される。
このため、そのようなてんかん病型である、良性新生児てんかん乳児悪性焦点移動性部分発作、夜間前頭葉てんかん、PCDH19関連てんかん、および片麻痺性片頭痛で既存の遺伝子異常が発見されない症例の収集をおこなった。すなわち臨床上で上記のてんかん病型の診断を得た患者より収集した検体を用いて既知の遺伝子変異をスクリーニングしたのち、変異が見いだされなかった検体を収集した。
またこれとは別に、いまだ明確な責任遺伝子異常が同定されていない、単純性熱性けいれんの症例を収集した。以上を次世代シークエンサーを用いてエクソームシークエンスを実施した。
今後は得られたデータをバイオインフォマティクスにより絞り込み、原因遺伝子異常を同定する予定である。

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

全国規模で希少疾患である良性新生児てんかん、乳児悪性焦点移動性部分発作、夜間前頭葉てんかん、PCDH19関連てんかん、片麻痺性片頭痛の収集を行った。そのなかでは、良性新生児てんかんから既知の遺伝子が原因でない典型例9家系の発端者9名のエクソーム解析を行った。同様に夜間前頭葉てんかんの9例に対しエクソームシークエンスを終了した。片麻痺性片頭痛に対しても4例で、PCDH19関連てんかんでは3家系の9名でのエクソームシークエンスを実施中である。熱性けいれんでは典型的な熱性けいれんの10家系10名でエクソームシークエンスを実施した。現在データを解析中である。

Strategy for Future Research Activity

患者収集と既知遺伝子変異の検索は乳児悪性焦点移動性部分発作に対して行う。また、エクソーム解析が終わったてんかん病型は、新規遺伝子変異、中枢神経発現の遺伝子に絞りこむなどの条件設定をバイオインフォマティクスで行い、遺伝子変異を絞り、さらに収集している同型のてんかんで同じ変異が見いだされるかなどの検討を行い、責任遺伝子を同定する予定である。
以上の方策によっても責任遺伝子変異が絞り込めないものについては積極的にトリオ検体の解析を行い、研究の達成をめざす。

Research Products

• [Journal Article] SCN1A testing for epilepsy: application in clinical practice. (2013)
  • Author(s): Hirose S, Scheffer IE, Marini C, De Jonghe P, Andermann E, Goldman AM, Kauffman M, Tan NC, Lowenstein DH, Sisodiya SM, Ottman R, Berkovic SF, Genetics Commission of the International League Against Epilepsy.
  • Journal Title: Epilepsia Volume: 54 Pages: 946-952
  • DOI: 10.1111/epi.12168
  • Peer Reviewed
• [Journal Article] A case of severe progressive early-onset epileptic encephalopathy: unique GABAergic interneuron distribution and imaging. (2013)
  • Author(s): Inoue T, Kawawaki H, Kuki I, Nabatame S, Tomonoh Y, Sukigara S, Horino A, Nukui M, Okazaki S, Tomiwa K, Kimura-Ohba S, Inoue T, Hirose S, Shiomi M, Itoh M.
  • Journal Title: J Neurol Sci. Volume: 327 Pages: 65-72
  • DOI: 10.1016/j.jns.2013.01.038
  • Peer Reviewed
• [Journal Article] Identification of ATP1A3 mutations by exome sequencing as the cause of alternating hemiplegia of childhood in Japanese patients. (2013)
  • Author(s): Ishii A, Saito Y, Mitsui J, Ishiura H, Yoshimura J, Arai H, Yamashita S, Kimura S, Oguni H, Morishita S, Tsuji S, Sasaki M, Hirose S.
  • Journal Title: PLoS ONE Volume: 8 Pages: e56120
  • DOI: 10.1371/journal.pone.0056120
  • Peer Reviewed
• [Journal Article] Genetic analysis of PRRT2 for benign infantile epilepsy, infantile convulsions with choreoathetosis syndrome, and benign convulsions with mild gastroenteritis. (2013)
  • Author(s): Ishii A, Yasumoto S, Ihara Y, Inoue T, Fujita T, Nakamura N, Ohfu M, Yamashita Y, Takatsuka H, Taga T, Miyata R, Ito M, Tsuchiya H, Matsuoka T, Kitao T, Murakami K, Lee WT, Kaneko S, Hirose S.
  • Journal Title: Brain Dev Volume: 35 Pages: 524-530
  • DOI: 10.1016/j.braindev.2012.09.006.
  • Peer Reviewed
• [Journal Article] PCDH19-related female-limited epilepsy: further details regarding early clinical features and therapeutic efficacy. (2013)
  • Author(s): Higurashi N, Nakamura M, Sugai M, Ohfu M, Sakauchi M, Sugawara Y, Nakamura K, Kato M, Usui D, Mogami Y, Fujiwara Y, Ito T, Ikeda H, Imai K, Takahashi Y, Nukui M, Inoue T, Okazaki S, Kirino T, Tomonoh Y, Inoue T, Takano K, Shimakawa S, Hirose S.
  • Journal Title: Epilepsy Res. Volume: 106 Pages: 191-199
  • DOI: 10.1016/j.eplepsyres.2013.04.005
  • Peer Reviewed
• [Journal Article] A human Dravet syndrome model from patient induced pluripotent stem cells. (2013)
  • Author(s): Higurashi N, Uchida T, Lossin C, Misumi Y, Okada Y, Akamatsu W, Imaizumi Y, Zhang B, Nabeshima K, Mori MX, Katsurabayashi S, Shirasaka Y, Okano H, Hirose S.
  • Journal Title: Mol Brain Volume: 6 Pages: 19
  • DOI: 10.1186/1756-6606-6-19.
  • Peer Reviewed
• [Journal Article] A recurrent KCNT1 mutation in two sporadic cases with malignant migrating partial seizures in infancy (2013)
  • Author(s): Ishii A, Shioda M, Okumura A, Kidokoro H, Sakauchi M, Shimada S, Shimizu T, Osawa M, Hirose S, Yamamoto T.
  • Journal Title: Gene Volume: 531 Pages: 467-471
  • DOI: 10.1016/j.gene.2013.08.096
  • Peer Reviewed
• [Journal Article] Current Trends in Dravet syndrome Research. (2013)
  • Author(s): Higurashi N, Uchida T, Hirose S, Okano H.
  • Journal Title: J Neurol Neurophysiol Volume: 4 Pages: 152
  • DOI: 10.4172/2155-9562.1000152
  • Peer Reviewed
• [Journal Article] A novel prophylactic effect of furosemide treatment on autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). (2013)
  • Author(s): Yamada J, Zhu G, Okada M, Hirose S, Yoshida S, Shiba Y, Migita K, Mori F, Sugawara T, Chen L, Liu F, Yoshida S, Ueno S, Kaneko S.
  • Journal Title: Epilepsy Res. Volume: 107 Pages: 127-137
  • DOI: 10.1016/j.eplepsyres.2013.08.018
  • Peer Reviewed
• [Journal Article] ADORA2A polymorphism predisposes children to encephalopathy with febrile status epilepticus. (2013)
  • Author(s): Shinohara M, Saitoh M, Nishizawa D, Ikeda K, Hirose S, Takanashi J, Takita J, Kikuchi K, Kubota M, Yamanaka G, Shiihara T, Kumakura A, Kikuchi M, Toyoshima M, Goto T, Yamanouchi H, Mizuguchi M.
  • Journal Title: Neurology. Volume: 80 Pages: 1571-1576
  • DOI: 10.1212/WNL.0b013e31828f18d8
  • Peer Reviewed
• [Journal Article] Detection of SCN1A mutations in patients with severe myclonic epilepsy in infancy by custom resequence array. (2013)
  • Author(s): Sugawara T, Yoshida S, Onodera N, Wada K, Hirose S, Kaneko S.
  • Journal Title: Journal of Epileptology. Volume: 21 Pages: 5-13
  • Peer Reviewed
• [Journal Article] Novel HCN2 Mutation Contributes to Febrile Seizures by Shifting the Channel's Kinetics in a Temperature-Dependent Manner. (2013)
  • Author(s): Nakamura Y, Shi X, Numata T, Mori Y, Inoue R, Lossin C, Baram TZ, Hirose S.
  • Journal Title: PLoS ONE. Volume: 8 Pages: e80376.
  • DOI: 10.1371/journal.pone.0080376.
  • Peer Reviewed
• [Journal Article] Properties of a novel GABAA receptor γ2 subunit mutation associated with seizures. (2013)
  • Author(s): Migita K, Yamada J, Nikaido Y, Shi X, Kaneko S, Hirose S, Ueno S.
  • Journal Title: J Pharmacol Sci. Volume: 121 Pages: 84-7
  • Peer Reviewed
• [Journal Article] Oral mexiletine for lidocaine-responsive neonatal epilepsy. (2013)
  • Author(s): Nakazawa M, Okumura A, Niijima S, Yamashita S, Shimono K, Hirose S, Shimizu T.
  • Journal Title: Brain Dev Volume: 35 Pages: 667-9.
  • DOI: 10.1016/j.braindev.2012.10.011
  • Peer Reviewed
• [Journal Article] The effect of SCN1A mutations on patient-derived GABAergic neurons: what are the implications for future Dravet syndrome therapeutics? (2013)
  • Author(s): Higurashi N, Okano H, Hirose S.
  • Journal Title: Future Neurol. Volume: 8 Pages: 487-489
  • DOI: 10.2217/FNL.13.34
  • Peer Reviewed
• [Presentation] Novel HCN2 mutation found in febrile seizure patients affects temperature sensitivity (2013)
  • Author(s): Nakamura Y, Shi X, Numata T, Mori Y, Inoue R, Hirose S.
  • Organizer: The 11th Korea-Japan Joint Symposium of Brain Sciences,and Cardiac and Smooth Muscle Sciences
  • Place of Presentation: Hamamatsu, Japan
  • Year and Date: 20130904-20130907
• [Presentation] Molecular basis of benign familial infantile epilepsy and related syndromes (2013)
  • Author(s): Hirose S
  • Organizer: ３０Th international Epilepsy Congress
  • Place of Presentation: Montreal, Canada
  • Year and Date: 20130623-20130627
• [Presentation] KCNQ2 and KCNQ3 abnormalities in benign neonatal epilepsy (BNE): a genetic analysis of BNE in Japan (2013)
  • Author(s): Ihara Y, Ishii A, Kaneko S, Hirose S, The Epilepsy Genetic Study Group Japan
  • Organizer: ３０Th international Epilepsy Congress
  • Place of Presentation: Montreal, Canada
  • Year and Date: 20130623-20130627
• [Presentation] Identification of ATP1A3 mutations ｂｙ exome sequencing as the cause of alternating hemiplegia of childhood in Japan (2013)
  • Author(s): Ishii A, Saito Y, Mitsui J, Ishiura H, Yoshimura J，Arai H, Yamashita S, Kimura S, Oguni H, Morishita S, Tsuji S, Sasaki M, Hirose S.
  • Organizer: ３０Th international Epilepsy Congress
  • Place of Presentation: Montreal, Canada
  • Year and Date: 20130623-20130627
• [Presentation] Frequency of Mutations of KCNQ2 and KCNQ3 in Benign Neonatal Epilepsy in Japan (2013)
  • Author(s): Hirose S, Ihara Y, Ishii A.
  • Organizer: Korean Epilepsy Congress 2013
  • Place of Presentation: Seoul, Korea
  • Year and Date: 20130613-20130615
• [Presentation] KCNQ2 Mutation Enhances Firing Activity of Gabaergic Interneurons in the Hippocampus of Neonatal Mice (2013)
  • Author(s): Uchida T, Deshimaru M, Koyama S, Yanagawa Y, Hirose S.
  • Organizer: Korean Epilepsy Congress 2013
  • Place of Presentation: Seoul, Korea
  • Year and Date: 20130613-20130615
• [Presentation] Electrophysiogical Analysis of Mutant HCN Channels Found in Febrile Seizure Patients (2013)
  • Author(s): Nakamura Y, Shi X, Numata T, Mori Y, Inoue R, Hirose S.
  • Organizer: Korean Epilepsy Congress 2013
  • Place of Presentation: Seoul, Korea
  • Year and Date: 20130613-20130615
• [Presentation] A Geneic analysis of Benign Neonatal Epilepsy in Japan (2013)
  • Author(s): Ihara Y, Ishii A, Kaneko S, Hirose S
  • Organizer: International Symposium on Neonatal Seizures and Related Disorders(ISNS)The 15th Annual Meeting of Infantile Seizure Society(ISS)
  • Place of Presentation: Tokyo,Japan
  • Year and Date: 20130412-20130414
• [Book] 遺伝学的診断マニュアル (2013)
  • Author(s): 廣瀨伸一
  • Total Pages: 5
  • Publisher: 稀少難治てんかん診療マニュアル