Genetic Variant KCNA1:p.Arg131Arg (chr12-4911769-C-A) – ACMG Classification: Likely_benign (-1 pts)

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 2P and 3B. PM2BP4_ModerateBP7

The NM_000217.3(KCNA1):c.391C>A(p.Arg131Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R131R) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 31)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KCNA1
NM_000217.3 synonymous

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.09

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

KCNA1 links:

ENSG00000256654 (HGNC:):

ENSG00000256654 links:

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new If you want to explore the variant's impact on the transcript NM_000217.3, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.4).

BP7

Synonymous conserved (PhyloP=1.09 with no splicing effect.

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNA1	NM_000217.3	MANE Select	c.391C>A	p.Arg131Arg	synonymous	Exon 2 of 2	NP_000208.2	Q09470

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
KCNA1	ENST00000382545.5	TSL:4 MANE Select	c.391C>A	p.Arg131Arg	synonymous	Exon 2 of 2	ENSP00000371985.3	Q09470
KCNA1	ENST00000639306.1	TSL:5	n.229C>A		non_coding_transcript_exon	Exon 1 of 2	ENSP00000492506.1	A0A1W2PRI2
ENSG00000256654	ENST00000541095.1	TSL:3	n.105+1297C>A		intron	N/A

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00

AC:

AN:

251404

AF XY:

0.00

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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

Data not reliable, filtered out with message: AC0

AF:

0.00

AC:

AN:

1461814

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727190

African (AFR)

AF:

0.00

AC:

AN:

33472

American (AMR)

AF:

0.00

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:

53412

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111960

Other (OTH)

AF:

0.00

AC:

AN:

60394

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.40

CADD

Benign

(source)

DANN

Benign

0.63

PhyloP100

1.1

PromoterAI

-0.050

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

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

ClinVar

Computational scores

Splicing

Publications

Other links and lift over