Molecular and pathological effects of a modifier gene on deficiency of the sodium channel Scn8a (Na(v)1.6)
- PMID: 12374766
- DOI: 10.1093/hmg/11.22.2765
Molecular and pathological effects of a modifier gene on deficiency of the sodium channel Scn8a (Na(v)1.6)
Abstract
Scn8a encodes an abundant, widely distributed voltage-gated sodium channel found throughout the central and peripheral nervous systems. Mice with different mutant alleles of Scn8a provide models of the movement disorders ataxia, dystonia, tremor and progressive paralysis. We previously reported that the phenotype of the hypomorphic allele of Scn8a, medJ, is dependent upon an unlinked modifier locus, Scnm1. Strain C57BL/6J carries a sensitive allele of the modifier locus that results in juvenile lethality. We now provide evidence that the modifier acts on the splicing efficiency of the mutant splice donor site. Mutant mice display either 90% or 95% reduction in the proportion of correctly spliced mRNA, depending on modifier genotype. The abundance of the channel protein, Na(v)1.6, is also reduced by an order of magnitude in medJ mice, resulting in delayed maturation of nodes of Ranvier, slowed nerve conduction velocity, reduced muscle mass and reduction of brain metabolic activity. medJ mice provide a model for the physiological effects of sodium channel deficiency and the molecular mechanism of bigenic disease.
Similar articles
-
Dystonia associated with mutation of the neuronal sodium channel Scn8a and identification of the modifier locus Scnm1 on mouse chromosome 3.Hum Mol Genet. 1999 Mar;8(3):471-9. doi: 10.1093/hmg/8.3.471. Hum Mol Genet. 1999. PMID: 9949206
-
SCNM1, a putative RNA splicing factor that modifies disease severity in mice.Science. 2003 Aug 15;301(5635):967-9. doi: 10.1126/science.1086187. Science. 2003. PMID: 12920299
-
Single amino acid deletion in transmembrane segment D4S6 of sodium channel Scn8a (Nav1.6) in a mouse mutant with a chronic movement disorder.Neurobiol Dis. 2016 May;89:36-45. doi: 10.1016/j.nbd.2016.01.018. Epub 2016 Jan 22. Neurobiol Dis. 2016. PMID: 26807988 Free PMC article.
-
Mutations of voltage-gated sodium channels in movement disorders and epilepsy.Novartis Found Symp. 2002;241:72-81; discussion 82-6, 226-32. Novartis Found Symp. 2002. PMID: 11771652 Review.
-
Allelic mutations of the sodium channel SCN8A reveal multiple cellular and physiological functions.Genetica. 2004 Sep;122(1):37-45. doi: 10.1007/s10709-004-1441-9. Genetica. 2004. PMID: 15619959 Review.
Cited by
-
Pathogenesis and new candidate treatments for infantile spasms and early life epileptic encephalopathies: A view from preclinical studies.Neurobiol Dis. 2015 Jul;79:135-49. doi: 10.1016/j.nbd.2015.04.015. Epub 2015 May 9. Neurobiol Dis. 2015. PMID: 25968935 Free PMC article. Review.
-
Sodium channel SCN8A (Nav1.6): properties and de novo mutations in epileptic encephalopathy and intellectual disability.Front Genet. 2013 Oct 28;4:213. doi: 10.3389/fgene.2013.00213. Front Genet. 2013. PMID: 24194747 Free PMC article. Review.
-
Cerebellum-related characteristics of Scn8a-mutant mice.Cerebellum. 2009 Sep;8(3):192-201. doi: 10.1007/s12311-009-0110-z. Epub 2009 May 8. Cerebellum. 2009. PMID: 19424768 Review.
-
Sodium channelopathies in neurodevelopmental disorders.Nat Rev Neurosci. 2021 Mar;22(3):152-166. doi: 10.1038/s41583-020-00418-4. Epub 2021 Feb 2. Nat Rev Neurosci. 2021. PMID: 33531663 Free PMC article. Review.
-
Conduction block in PMP22 deficiency.J Neurosci. 2010 Jan 13;30(2):600-8. doi: 10.1523/JNEUROSCI.4264-09.2010. J Neurosci. 2010. PMID: 20071523 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Medical
Molecular Biology Databases