rs763353895

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_004974.4(KCNA2):​c.193C>T​(p.Arg65*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000205 in 1,461,878 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

KCNA2
NM_004974.4 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2U:1

Conservation

PhyloP100: 5.68
Variant links:
Genes affected
KCNA2 (HGNC:6220): (potassium voltage-gated channel subfamily A member 2) Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, members of which allow nerve cells to efficiently repolarize following an action potential. The coding region of this gene is intronless, and the gene is clustered with genes KCNA3 and KCNA10 on chromosome 1. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 76 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-110604590-G-A is Pathogenic according to our data. Variant chr1-110604590-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 476049.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNA2NM_004974.4 linkc.193C>T p.Arg65* stop_gained Exon 3 of 3 ENST00000316361.10 NP_004965.1 P16389-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNA2ENST00000316361.10 linkc.193C>T p.Arg65* stop_gained Exon 3 of 3 2 NM_004974.4 ENSP00000314520.4 P16389-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251450
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135906
show subpopulations
Gnomad AFR exome
AF:
0.0000616
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461878
Hom.:
0
Cov.:
34
AF XY:
0.00000138
AC XY:
1
AN XY:
727238
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
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:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 32 Pathogenic:1Uncertain:1
Jul 05, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 476049). This premature translational stop signal has been observed in individuals with autosomal recessive KCNA2-related epilepsy (PMID: 27457812; Invitae). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs763353895, gnomAD 0.007%). This sequence change creates a premature translational stop signal (p.Arg65*) in the KCNA2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 435 amino acid(s) of the KCNA2 protein. -

Oct 31, 2018
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: flagged submission
Collection Method: clinical testing

- -

Seizure Pathogenic:1
Jan 05, 2024
Génétique des Maladies du Développement, Hospices Civils de Lyon
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.63
CADD
Pathogenic
38
DANN
Uncertain
1.0
Eigen
Uncertain
0.58
Eigen_PC
Uncertain
0.45
FATHMM_MKL
Uncertain
0.95
D
Vest4
0.78
GERP RS
3.8

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.

Other links and lift over

dbSNP: rs763353895; hg19: chr1-111147212; COSMIC: COSV60370708; COSMIC: COSV60370708; API