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Abstract
KCNQ2 mutations are associated with various types of epilepsy as well as peripheral nerve hyperexcitability (PNH). We report a 12-year-old boy with a de novo in frame deletion in KCNQ2, presenting with muscle cramps without epilepsy. The present deletion has already been described in a patient with epilepsy but never associated with PNH. We give a detailed description of the clinical phenotype and provide hypothetical therapeutic options. Our case highlights the fact that potassium channelopathies must be considered in the differential diagnostic considerations of peripheral nerve hyperexcitability, even in the absence of seizures.
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Copyright (c) 2020 Matthias De Wachter, Marije Meuwissen, Charlotte Dielman, Marian Moens
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References
- Hart IK, Maddison P, Newsom-Davis J, Vincent A, Mills KR (2002) Phenotypic variants of autoimmune peripheral nerve hyperexcitability. Brain 125 (Pt 8):1887-95. DOI: 10.1093/brain/awf178 PMID: 12135978.
- Wuttke TV, Jurkat-Rott K, Paulus W, Garncarek M, Lehmann-Horn F, Lerche H (2007) Peripheral nerve hyperexcitability due to dominant-negative KCNQ2 mutations. Neurology 69 (22):2045-53. DOI: 10.1212/01.wnl.0000275523.95103.36 PMID: 17872363.
- Dedek K, Kunath B, Kananura C, Reuner U, Jentsch TJ, Steinlein OK (2001) Myokymia and neonatal epilepsy caused by a mutation in the voltage sensor of the KCNQ2 K+ channel. Proc Natl Acad Sci U S A 98 (21):12272-7. DOI: 10.1073/pnas.211431298 PMID: 11572947.
- Neubauer BA, Waldegger S, Heinzinger J, Hahn A, Kurlemann G, Fiedler B | display-authors=etal (2008) KCNQ2 and KCNQ3 mutations contribute to different idiopathic epilepsy syndromes. Neurology 71 (3):177-83. DOI: 10.1212/01.wnl.0000317090.92185.ec PMID: 18625963.
- Biervert C, Schroeder BC, Kubisch C, Berkovic SF, Propping P, Jentsch TJ | display-authors=etal (1998) A potassium channel mutation in neonatal human epilepsy. Science 279 (5349):403-6. DOI: 10.1126/science.279.5349.403 PMID: 9430594.
- Brown DA, Passmore GM (2009) Neural KCNQ (Kv7) channels. Br J Pharmacol 156 (8):1185-95. DOI: 10.1111/j.1476-5381.2009.00111.x PMID: 19298256.
- Delmas P, Brown DA (2005) Pathways modulating neural KCNQ/M (Kv7) potassium channels. Nat Rev Neurosci 6 (11):850-62. DOI: 10.1038/nrn1785 PMID: 16261179.
- Al Yazidi G, Shevell MI, Srour M (2017) Two Novel KCNQ2 Mutations in 2 Families With Benign Familial Neonatal Convulsions. Child Neurol Open 4 ():2329048X17691396. DOI: 10.1177/2329048X17691396 PMID: 28503627.
- Singh NA, Charlier C, Stauffer D, DuPont BR, Leach RJ, Melis R | display-authors=etal (1998) A novel potassium channel gene, KCNQ2, is mutated in an inherited epilepsy of newborns. Nat Genet 18 (1):25-9. DOI: 10.1038/ng0198-25 PMID: 9425895.
- Rajakulendran S, Tan SV, Matthews E, Tomlinson SE, Labrum R, Sud R | display-authors=etal (2009) A patient with episodic ataxia and paramyotonia congenita due to mutations in KCNA1 and SCN4A. Neurology 73 (12):993-5. DOI: 10.1212/WNL.0b013e3181b87959 PMID: 19770477.
- Elangovan C, Morawo A, Ahmed A (2018) Current Treatment Options for Peripheral Nerve Hyperexcitability Syndromes. Curr Treat Options Neurol 20 (7):23. DOI: 10.1007/s11940-018-0510-9 PMID: 29808385.
- Suetterlin K, Männikkö R, Hanna MG (2014) Muscle channelopathies: recent advances in genetics, pathophysiology and therapy. Curr Opin Neurol 27 (5):583-90. DOI: 10.1097/WCO.0000000000000127 PMID: 25188014
References
Hart IK, Maddison P, Newsom-Davis J, Vincent A, Mills KR (2002) Phenotypic variants of autoimmune peripheral nerve hyperexcitability. Brain 125 (Pt 8):1887-95. DOI: 10.1093/brain/awf178 PMID: 12135978.
Wuttke TV, Jurkat-Rott K, Paulus W, Garncarek M, Lehmann-Horn F, Lerche H (2007) Peripheral nerve hyperexcitability due to dominant-negative KCNQ2 mutations. Neurology 69 (22):2045-53. DOI: 10.1212/01.wnl.0000275523.95103.36 PMID: 17872363.
Dedek K, Kunath B, Kananura C, Reuner U, Jentsch TJ, Steinlein OK (2001) Myokymia and neonatal epilepsy caused by a mutation in the voltage sensor of the KCNQ2 K+ channel. Proc Natl Acad Sci U S A 98 (21):12272-7. DOI: 10.1073/pnas.211431298 PMID: 11572947.
Neubauer BA, Waldegger S, Heinzinger J, Hahn A, Kurlemann G, Fiedler B | display-authors=etal (2008) KCNQ2 and KCNQ3 mutations contribute to different idiopathic epilepsy syndromes. Neurology 71 (3):177-83. DOI: 10.1212/01.wnl.0000317090.92185.ec PMID: 18625963.
Biervert C, Schroeder BC, Kubisch C, Berkovic SF, Propping P, Jentsch TJ | display-authors=etal (1998) A potassium channel mutation in neonatal human epilepsy. Science 279 (5349):403-6. DOI: 10.1126/science.279.5349.403 PMID: 9430594.
Brown DA, Passmore GM (2009) Neural KCNQ (Kv7) channels. Br J Pharmacol 156 (8):1185-95. DOI: 10.1111/j.1476-5381.2009.00111.x PMID: 19298256.
Delmas P, Brown DA (2005) Pathways modulating neural KCNQ/M (Kv7) potassium channels. Nat Rev Neurosci 6 (11):850-62. DOI: 10.1038/nrn1785 PMID: 16261179.
Al Yazidi G, Shevell MI, Srour M (2017) Two Novel KCNQ2 Mutations in 2 Families With Benign Familial Neonatal Convulsions. Child Neurol Open 4 ():2329048X17691396. DOI: 10.1177/2329048X17691396 PMID: 28503627.
Singh NA, Charlier C, Stauffer D, DuPont BR, Leach RJ, Melis R | display-authors=etal (1998) A novel potassium channel gene, KCNQ2, is mutated in an inherited epilepsy of newborns. Nat Genet 18 (1):25-9. DOI: 10.1038/ng0198-25 PMID: 9425895.
Rajakulendran S, Tan SV, Matthews E, Tomlinson SE, Labrum R, Sud R | display-authors=etal (2009) A patient with episodic ataxia and paramyotonia congenita due to mutations in KCNA1 and SCN4A. Neurology 73 (12):993-5. DOI: 10.1212/WNL.0b013e3181b87959 PMID: 19770477.
Elangovan C, Morawo A, Ahmed A (2018) Current Treatment Options for Peripheral Nerve Hyperexcitability Syndromes. Curr Treat Options Neurol 20 (7):23. DOI: 10.1007/s11940-018-0510-9 PMID: 29808385.
Suetterlin K, Männikkö R, Hanna MG (2014) Muscle channelopathies: recent advances in genetics, pathophysiology and therapy. Curr Opin Neurol 27 (5):583-90. DOI: 10.1097/WCO.0000000000000127 PMID: 25188014