4rly

Structural highlights

Disease

SCN2A_HUMAN Defects in SCN2A are the cause of seizures, benign familial infantile type 3 (BFIS3) [MIM:607745. An autosomal dominant disorder in which afebrile seizures occur in clusters during the first year of life, without neurologic sequelae.^{[1] [2] [3] [4]} Defects in SCN2A are the cause of epileptic encephalopathy early infantile type 11 (EIEE11) [MIM:613721. EIEE11 is an autosomal dominant seizure disorder characterized by infantile onset of refractory seizures with resultant delayed neurologic development and persistent neurologic abnormalities.^{[5] [6]} ANK2_HUMAN Romano-Ward syndrome. Long QT syndrome 4 (LQT4) [MIM:600919: A heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. Long QT syndrome type 4 shows many atypical features compared to classical long QT syndromes, including pronounced sinus bradycardia, polyphasic T waves and atrial fibrillation. Cardiac repolarization defects may be not as severe as in classical LQT syndromes and prolonged QT interval on EKG is not a consistent feature. Note=The disease is caused by mutations affecting the gene represented in this entry.^{[7] [8]}

Function

SCN2A_HUMAN Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na(+) ions may pass in accordance with their electrochemical gradient.ANK2_HUMAN In skeletal muscle, required for proper localization of DMD and DCTN4 and for the formation and/or stability of a special subset of microtubules associated with costameres and neuromuscular junctions (By similarity). Attaches integral membrane proteins to cytoskeletal elements. Also binds to cytoskeletal proteins. Required for coordinate assembly of Na/Ca exchanger, Na/K ATPase and InsP3 receptor at sarcoplasmic reticulum sites in cardiomyocytes. Required for the coordinated expression of the Na/K ATPase, Na/Ca exchanger and beta-2-spectrin (SPTBN1) in the inner segment of rod photoreceptors. Required for expression and targeting of SPTBN1 in neonatal cardiomyocytes and for the regulation of neonatal cardiomyocyte contraction rate.^[9]

References

1. ↑ Sugawara T, Tsurubuchi Y, Agarwala KL, Ito M, Fukuma G, Mazaki-Miyazaki E, Nagafuji H, Noda M, Imoto K, Wada K, Mitsudome A, Kaneko S, Montal M, Nagata K, Hirose S, Yamakawa K. A missense mutation of the Na+ channel alpha II subunit gene Na(v)1.2 in a patient with febrile and afebrile seizures causes channel dysfunction. Proc Natl Acad Sci U S A. 2001 May 22;98(11):6384-9. PMID:11371648 doi:10.1073/pnas.111065098
2. ↑ Heron SE, Crossland KM, Andermann E, Phillips HA, Hall AJ, Bleasel A, Shevell M, Mercho S, Seni MH, Guiot MC, Mulley JC, Berkovic SF, Scheffer IE. Sodium-channel defects in benign familial neonatal-infantile seizures. Lancet. 2002 Sep 14;360(9336):851-2. PMID:12243921 doi:10.1016/S0140-6736(02)09968-3
3. ↑ Berkovic SF, Heron SE, Giordano L, Marini C, Guerrini R, Kaplan RE, Gambardella A, Steinlein OK, Grinton BE, Dean JT, Bordo L, Hodgson BL, Yamamoto T, Mulley JC, Zara F, Scheffer IE. Benign familial neonatal-infantile seizures: characterization of a new sodium channelopathy. Ann Neurol. 2004 Apr;55(4):550-7. PMID:15048894 doi:10.1002/ana.20029
4. ↑ Liao Y, Deprez L, Maljevic S, Pitsch J, Claes L, Hristova D, Jordanova A, Ala-Mello S, Bellan-Koch A, Blazevic D, Schubert S, Thomas EA, Petrou S, Becker AJ, De Jonghe P, Lerche H. Molecular correlates of age-dependent seizures in an inherited neonatal-infantile epilepsy. Brain. 2010 May;133(Pt 5):1403-14. doi: 10.1093/brain/awq057. Epub 2010 Apr 5. PMID:20371507 doi:10.1093/brain/awq057
5. ↑ Ogiwara I, Ito K, Sawaishi Y, Osaka H, Mazaki E, Inoue I, Montal M, Hashikawa T, Shike T, Fujiwara T, Inoue Y, Kaneda M, Yamakawa K. De novo mutations of voltage-gated sodium channel alphaII gene SCN2A in intractable epilepsies. Neurology. 2009 Sep 29;73(13):1046-53. doi: 10.1212/WNL.0b013e3181b9cebc. PMID:19786696 doi:10.1212/WNL.0b013e3181b9cebc
6. ↑ Liao Y, Anttonen AK, Liukkonen E, Gaily E, Maljevic S, Schubert S, Bellan-Koch A, Petrou S, Ahonen VE, Lerche H, Lehesjoki AE. SCN2A mutation associated with neonatal epilepsy, late-onset episodic ataxia, myoclonus, and pain. Neurology. 2010 Oct 19;75(16):1454-8. doi: 10.1212/WNL.0b013e3181f8812e. PMID:20956790 doi:10.1212/WNL.0b013e3181f8812e
7. ↑ Mohler PJ, Schott JJ, Gramolini AO, Dilly KW, Guatimosim S, duBell WH, Song LS, Haurogne K, Kyndt F, Ali ME, Rogers TB, Lederer WJ, Escande D, Le Marec H, Bennett V. Ankyrin-B mutation causes type 4 long-QT cardiac arrhythmia and sudden cardiac death. Nature. 2003 Feb 6;421(6923):634-9. PMID:12571597 doi:10.1038/nature01335
8. ↑ Mohler PJ, Splawski I, Napolitano C, Bottelli G, Sharpe L, Timothy K, Priori SG, Keating MT, Bennett V. A cardiac arrhythmia syndrome caused by loss of ankyrin-B function. Proc Natl Acad Sci U S A. 2004 Jun 15;101(24):9137-42. Epub 2004 Jun 3. PMID:15178757 doi:10.1073/pnas.0402546101
9. ↑ Mohler PJ, Schott JJ, Gramolini AO, Dilly KW, Guatimosim S, duBell WH, Song LS, Haurogne K, Kyndt F, Ali ME, Rogers TB, Lederer WJ, Escande D, Le Marec H, Bennett V. Ankyrin-B mutation causes type 4 long-QT cardiac arrhythmia and sudden cardiac death. Nature. 2003 Feb 6;421(6923):634-9. PMID:12571597 doi:10.1038/nature01335