rs1553181236

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_004974.4(KCNA2):​c.1304G>C​(p.Cys435Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,878 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. C435Y) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNA2
NM_004974.4 missense

Scores

2
6
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.88

Publications

1 publications found
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]
KCNA2 Gene-Disease associations (from GenCC):
  • developmental and epileptic encephalopathy, 32
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • genetic developmental and epileptic encephalopathy
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • undetermined early-onset epileptic encephalopathy
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.351278).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNA2NM_004974.4 linkc.1304G>C p.Cys435Ser missense_variant 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.1304G>C p.Cys435Ser missense_variant Exon 3 of 3 2 NM_004974.4 ENSP00000314520.4 P16389-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461878
Hom.:
0
Cov.:
34
AF XY:
0.00000138
AC XY:
1
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111998
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Developmental and epileptic encephalopathy, 32 Uncertain:1
Oct 07, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with KCNA2-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces cysteine with serine at codon 435 of the KCNA2 protein (p.Cys435Ser). The cysteine residue is highly conserved and there is a moderate physicochemical difference between cysteine and serine. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.087
BayesDel_addAF
Uncertain
0.13
D
BayesDel_noAF
Uncertain
-0.060
CADD
Benign
23
DANN
Benign
0.80
DEOGEN2
Pathogenic
0.82
D;.;.;D;D;D;D;.
Eigen
Benign
-0.035
Eigen_PC
Benign
0.12
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.79
.;T;T;.;.;.;T;T
M_CAP
Benign
0.051
D
MetaRNN
Benign
0.35
T;T;T;T;T;T;T;T
MetaSVM
Uncertain
0.44
D
MutationAssessor
Benign
1.4
L;.;.;L;L;L;L;.
PhyloP100
4.9
PrimateAI
Uncertain
0.78
T
PROVEAN
Pathogenic
-4.5
.;.;.;.;D;.;D;.
REVEL
Uncertain
0.36
Sift
Benign
0.19
.;.;.;.;T;.;T;.
Sift4G
Benign
0.30
T;.;.;.;T;.;T;.
Polyphen
0.0
B;.;.;B;B;B;B;.
Vest4
0.20
MutPred
0.47
Gain of disorder (P = 0.003);.;.;Gain of disorder (P = 0.003);Gain of disorder (P = 0.003);Gain of disorder (P = 0.003);Gain of disorder (P = 0.003);.;
MVP
0.66
MPC
1.4
ClinPred
0.43
T
GERP RS
4.9
Varity_R
0.40
gMVP
0.59
Mutation Taster
=74/26
polymorphism

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

Other links and lift over

dbSNP: rs1553181236; hg19: chr1-111146101; API