rs372539672

Positions:

chr12-4912827-A-T

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 1P and 7B. PP2BP4_ModerateBS1_SupportingBS2

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. 14/21 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

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 links:

(HGNC:):

links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNA1. . Gene score misZ 3.3255 (greater than the threshold 3.09). Trascript score misZ 3.8671 (greater than threshold 3.09). GenCC has associacion of gene with episodic kinesigenic dyskinesia 1, episodic ataxia type 1, developmental and epileptic encephalopathy, isolated autosomal dominant hypomagnesemia, Glaudemans type.

BP4

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

BS1

Variant frequency is greater than expected in population nfe. gnomad4_exome 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 gnomad4_exome. There are 64 alleles in male gnomad4_exome subpopulation. Median coverage is 34. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

BS2

High AC in GnomAd4 at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNA1	NM_000217.3 linkuse as main transcript	c.1449A>T	p.Gln483His	missense_variant	2/2	ENST00000382545.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNA1	ENST00000382545.5 linkuse as main transcript	c.1449A>T	p.Gln483His	missense_variant	2/2	4	NM_000217.3	P1
	ENST00000640877.1 linkuse as main transcript	n.606+2355A>T		intron_variant, non_coding_transcript_variant		5

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

GnomAD3 exomes

AF:

0.0000517

AC:

AN:

251354

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135854

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 SAS 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

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000111

Gnomad4 OTH exome

AF:

0.0000828

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

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

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Episodic ataxia type 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 19, 2024

This sequence change replaces glutamine, which is neutral and polar, with histidine, which is basic and polar, at codon 483 of the KCNA1 protein (p.Gln483His). This variant is present in population databases (rs372539672, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with KCNA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 586090). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt KCNA1 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Jul 15, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Benign

-0.047

BayesDel_noAF

Benign

-0.10

CADD

Benign

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

MutationTaster

Benign

1.0

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

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over