Table 8.

Notable KCNC3 Pathogenic Variants

Reference SequencesDNA Nucleotide ChangePredicted Protein ChangeComment [Reference]
NM_004977​.2
NP_004968​.2 		c.1259G>Ap.Arg420HisNonfunctional but expressed protein; adult-onset progressive ataxia 1
c.1268G>Ap.Arg423HisSlow channel activation; congenital-onset cerebellar hypoplasia, cerebellar ataxia, mild cognitive impairment, & seizures 2
c.1344C>Ap.Phe448LeuSlow channel closing; childhood-onset ataxia & often ID & seizures 3
c.1603G>Ap.Val535MetChildhood onset; cerebellar ataxia; mild ID [Duarri et al 2015]
c.1746_1754delp.Pro583_Pro585delCerebellar ataxia; mild cognitive impairment; seizures; dysarthria/dysphagia; hyperreflexia; pasticity; onset in 30s w/progression to severe disease over several decades [Khare et al 2018]

Variants listed in the table have been provided by the author. GeneReviews staff have not independently verified the classification of variants.

GeneReviews follows the standard naming conventions of the Human Genome Variation Society (varnomen​.hgvs.org). See Quick Reference for an explanation of nomenclature.

ID = intellectual disability

1.
2.
3.

From: Spinocerebellar Ataxia Type 13

Cover of GeneReviews®
GeneReviews® [Internet].
Adam MP, Feldman J, Mirzaa GM, et al., editors.
Seattle (WA): University of Washington, Seattle; 1993-2024.
Copyright © 1993-2024, University of Washington, Seattle. GeneReviews is a registered trademark of the University of Washington, Seattle. All rights reserved.

GeneReviews® chapters are owned by the University of Washington. Permission is hereby granted to reproduce, distribute, and translate copies of content materials for noncommercial research purposes only, provided that (i) credit for source (http://www.genereviews.org/) and copyright (© 1993-2024 University of Washington) are included with each copy; (ii) a link to the original material is provided whenever the material is published elsewhere on the Web; and (iii) reproducers, distributors, and/or translators comply with the GeneReviews® Copyright Notice and Usage Disclaimer. No further modifications are allowed. For clarity, excerpts of GeneReviews chapters for use in lab reports and clinic notes are a permitted use.

For more information, see the GeneReviews® Copyright Notice and Usage Disclaimer.

For questions regarding permissions or whether a specified use is allowed, contact: ude.wu@tssamda.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.