NM_000217.3:c.393G>A

Variant names:

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_StrongBP6_Very_StrongBP7BS1

The NM_000217.3(KCNA1):c.393G>A(p.Arg131Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000688 in 1,613,922 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

Frequency

Genomes: 𝑓 0.00035 ( 0 hom., cov: 31)

Exomes 𝑓: 0.000039 ( 0 hom. )

Consequence

KCNA1
NM_000217.3 synonymous

Scores

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:3

Conservation

PhyloP100: 0.363

Publications

0 publications found

Variant links:

Genes affected

KCNA1 (HGNC:6218): (potassium voltage-gated channel subfamily A member 1) This gene encodes a voltage-gated delayed potassium channel that is phylogenetically related to the Drosophila Shaker channel. The encoded protein has six putative transmembrane segments (S1-S6), and the loop between S5 and S6 forms the pore and contains the conserved selectivity filter motif (GYGD). The functional channel is a homotetramer. The N-terminus of the channel is associated with beta subunits that can modify the inactivation properties of the channel as well as affect expression levels. The C-terminus of the channel is complexed to a PDZ domain protein that is responsible for channel targeting. Mutations in this gene have been associated with myokymia with periodic ataxia (AEMK). [provided by RefSeq, Jul 2008]

KCNA1 Gene-Disease associations (from GenCC):

episodic ataxia type 1
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, ClinGen, Orphanet, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
episodic kinesigenic dyskinesia 1
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
isolated autosomal dominant hypomagnesemia, Glaudemans type
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
genetic developmental and epileptic encephalopathy
Inheritance: AR, AD Classification: SUPPORTIVE, LIMITED Submitted by: G2P, Orphanet

KCNA1 links:

ENSG00000256654 (HGNC:):

ENSG00000256654 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -17 ACMG points.

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.65).

BP6

Variant 12-4911771-G-A is Benign according to our data. Variant chr12-4911771-G-A is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 447610.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

BP7

Synonymous conserved (PhyloP=0.363 with no splicing effect.

BS1

Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000355 (54/152116) while in subpopulation AFR AF = 0.00126 (52/41420). AF 95% confidence interval is 0.000983. There are 0 homozygotes in GnomAd4. There are 27 alleles in the male GnomAd4 subpopulation. Median coverage is 31. This position passed quality control check.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000217.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNA1	NM_000217.3	MANE Select	c.393G>A	p.Arg131Arg	synonymous	Exon 2 of 2	NP_000208.2

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
KCNA1	ENST00000382545.5	TSL:4 MANE Select	c.393G>A	p.Arg131Arg	synonymous	Exon 2 of 2	ENSP00000371985.3
KCNA1	ENST00000639306.1	TSL:5	n.231G>A		non_coding_transcript_exon	Exon 1 of 2	ENSP00000492506.1
ENSG00000256654	ENST00000541095.1	TSL:3	n.105+1299G>A		intron	N/A

Frequencies

GnomAD3 genomes

AF:

0.000355

AC:

AN:

152116

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00126

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000835

AC:

AN:

251404

AF XY:

0.0000736

show subpopulations

Gnomad AFR exome

AF:

0.00117

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000390

AC:

AN:

1461806

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

727188

show subpopulations

African (AFR)

AF:

0.00134

AC:

AN:

33470

American (AMR)

AF:

0.000134

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.000173

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111950

Other (OTH)

AF:

0.0000497

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.507

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.000355

AC:

AN:

152116

Hom.:

Cov.:

AF XY:

0.000363

AC XY:

AN XY:

74282

show subpopulations

African (AFR)

AF:

0.00126

AC:

AN:

41420

American (AMR)

AF:

0.000131

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5164

South Asian (SAS)

AF:

0.00

AC:

AN:

4814

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.479

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.000427

Hom.:

Bravo

AF:

0.000495

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Episodic ataxia type 1

Benign:2

Dec 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Oct 29, 2021

Fulgent Genetics, Fulgent Genetics

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

not specified

Benign:1

Apr 06, 2017

Athena Diagnostics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.65

CADD

Benign

8.6

(source)

DANN

Benign

0.80

PhyloP100

0.36

PromoterAI

-0.029

Neutral

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over