Episodic ataxia/myokymia syndrome is associated with point mutations in the human potassium channel gene, KCNA1.
Episodic ataxia (EA) is a rare, familial disorder producing attacks of generalized ataxia, with normal or near-normal neurological function between attacks. One type of EA is characterized by brief episodes of ataxia with myokymia (rippling of muscles) evident between attacks. Linkage studies in four such families suggested localization of an EA/myokymia gene near the voltage gated K+ channel gene, KCNA1 (Kv1.1), on chromosome 12p. Mutation analysis of the KCNA1 coding region in these families identified four different missense point mutations present in the heterozygous state, indicating that EA/myokymia can result from mutations in this gene.
Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, Portland 97201.
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Browne
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Gancher
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Nutt
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Brunt
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Smith
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Kramer
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Litt
D000595:Amino Acid Sequence; D000818:Animals; D001259:Ataxia / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics; D005207:Fasciculation / Q000235:genetics*; D005260:Female; D005796:Genes; D006801:Humans; D051662:Kv1.1 Potassium Channel; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D010375:Pedigree; D017354:Point Mutation; D015221:Potassium Channels / Q000737:chemistry / Q000172:deficiency / Q000235:genetics* / Q000502:physiology; D024642:Potassium Channels, Voltage-Gated; D011487:Protein Conformation; D051381:Rats; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D051637:Shaker Superfamily of Potassium Channels; D013577:Syndrome
D029721:Drosophila Proteins; C496946:KCNA1 protein, human; C496947:Kcna1 protein, mouse; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; C496929:Sh protein, Drosophila; D051637:Shaker Superfamily of Potassium Channels; D051662:Kv1.1 Potassium Channel