NM_000217.3:c.1449A>T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 1P and 3B. PP2BP4_ModerateBS1_Supporting

The NM_000217.3(KCNA1):c.1449A>T(p.Gln483His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000083 in 1,613,900 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000088 ( 1 hom. )

Consequence

KCNA1
NM_000217.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 2.01

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: Likely_benign. The variant received -2 ACMG points.

PP2

Missense variant in the KCNA1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 33 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: 3.3255 (above the threshold of 3.09). Trascript score misZ: 3.8671 (above the threshold of 3.09). GenCC associations: The gene is linked to isolated autosomal dominant hypomagnesemia, Glaudemans type, episodic ataxia type 1, genetic developmental and epileptic encephalopathy, episodic kinesigenic dyskinesia 1.

BP4

Computational evidence support a benign effect (MetaRNN=0.14142987).

BS1

Variant frequency is greater than expected in population nfe. GnomAdExome4 allele frequency = 0.0000876 (128/1461722) while in subpopulation NFE AF = 0.000111 (123/1111878). AF 95% confidence interval is 0.0000947. There are 1 homozygotes in GnomAdExome4. There are 64 alleles in the male GnomAdExome4 subpopulation. Median coverage is 34. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

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.1449A>T	p.Gln483His	missense	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.1449A>T	p.Gln483His	missense	Exon 2 of 2	ENSP00000371985.3
KCNA1	ENST00000639306.1	TSL:5	n.1287A>T		non_coding_transcript_exon	Exon 1 of 2	ENSP00000492506.1
KCNA1	ENST00000639680.1	TSL:5	c.75+561A>T		intron	N/A	ENSP00000492218.1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000517

AC:

AN:

251354

AF XY:

0.0000515

show subpopulations

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:

0.000106

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000876

AC:

128

AN:

1461722

Hom.:

Cov.:

AF XY:

0.0000880

AC XY:

AN XY:

727178

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

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:

53398

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.000111

AC:

123

AN:

1111878

Other (OTH)

AF:

0.0000828

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

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:

0.0000394

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74346

show subpopulations

African (AFR)

AF:

0.0000241

AC:

AN:

41438

American (AMR)

AF:

0.00

AC:

AN:

15278

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10624

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000735

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.517

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:

0.0000900

Hom.:

Bravo

AF:

0.0000378

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000494

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.000237

ClinVar

ClinVar submissions as Germline

Significance:Uncertain significance

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Episodic ataxia type 1 (1)

not provided (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.047

BayesDel_noAF

Benign

-0.10

CADD

Benign

(source)

DANN

Benign

0.95

DEOGEN2

Benign

0.30

Eigen

Benign

-0.26

Eigen_PC

Benign

-0.084

FATHMM_MKL

Uncertain

0.87

LIST_S2

Benign

0.83

M_CAP

Benign

0.041

MetaRNN

Benign

0.14

MetaSVM

Uncertain

0.17

MutationAssessor

Benign

0.81

PhyloP100

2.0

PrimateAI

Uncertain

0.58

PROVEAN

Benign

-0.010

REVEL

Uncertain

0.34

Sift

Benign

0.16

Sift4G

Benign

0.11

Polyphen

0.0010

Vest4

0.17

MutPred

0.43

Gain of catalytic residue at T480 (P = 0)

MVP

0.85

MPC

1.1

ClinPred

0.17

GERP RS

4.2

Varity_R

0.095

gMVP

0.50

Mutation Taster

=72/28

polymorphism

(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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

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

ClinVar submissions as Germline

Computational scores

Splicing

Publications

Other links and lift over