rs145422660

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_012281.3(KCND2):​c.1473C>G​(p.His491Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,310 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. H491H) has been classified as Benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCND2
NM_012281.3 missense

Scores

2
8
9

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: -1.15

Publications

1 publications found
Variant links:
Genes affected
KCND2 (HGNC:6238): (potassium voltage-gated channel subfamily D member 2) Voltage-gated potassium (Kv) 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, shal-related subfamily, members of which form voltage-activated A-type potassium ion channels and are prominent in the repolarization phase of the action potential. This member mediates a rapidly inactivating, A-type outward potassium current which is not under the control of the N terminus as it is in Shaker channels. [provided by RefSeq, Jul 2008]
KCND2 Gene-Disease associations (from GenCC):
  • KCND2-related neurodevelopmental disorder with or without seizures
    Inheritance: AD Classification: MODERATE Submitted by: G2P
  • complex neurodevelopmental disorder
    Inheritance: AD Classification: LIMITED Submitted by: Illumina

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCND2NM_012281.3 linkc.1473C>G p.His491Gln missense_variant Exon 5 of 6 ENST00000331113.9 NP_036413.1 Q9NZV8A4D0V9
KCND2XM_047420346.1 linkc.1473C>G p.His491Gln missense_variant Exon 6 of 7 XP_047276302.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCND2ENST00000331113.9 linkc.1473C>G p.His491Gln missense_variant Exon 5 of 6 1 NM_012281.3 ENSP00000333496.4 Q9NZV8
KCND2ENST00000425288.1 linkc.228C>G p.His76Gln missense_variant Exon 4 of 5 4 ENSP00000415463.1 H7C445
KCND2ENST00000473190.1 linkn.288C>G non_coding_transcript_exon_variant Exon 2 of 3 4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000399
AC:
1
AN:
250540
AF XY:
0.00000739
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000290
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
AF:
6.84e-7
AC:
1
AN:
1461310
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726964
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33446
American (AMR)
AF:
0.0000224
AC:
1
AN:
44684
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39634
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53388
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111664
Other (OTH)
AF:
0.00
AC:
0
AN:
60358
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.325
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
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

Early myoclonic encephalopathy Uncertain:1
Feb 19, 2022
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. 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 KCND2 protein function. This variant has not been reported in the literature in individuals affected with KCND2-related conditions. This variant is present in population databases (rs145422660, gnomAD 0.003%). This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 491 of the KCND2 protein (p.His491Gln). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.93
BayesDel_addAF
Uncertain
0.074
D
BayesDel_noAF
Uncertain
-0.050
CADD
Benign
0.38
DANN
Uncertain
0.98
DEOGEN2
Uncertain
0.63
D
Eigen
Benign
-0.79
Eigen_PC
Benign
-0.92
FATHMM_MKL
Benign
0.33
N
LIST_S2
Uncertain
0.90
D
M_CAP
Uncertain
0.13
D
MetaRNN
Uncertain
0.50
T
MetaSVM
Benign
-0.44
T
MutationAssessor
Benign
2.0
M
PhyloP100
-1.1
PrimateAI
Pathogenic
0.82
D
PROVEAN
Benign
-1.8
N
REVEL
Uncertain
0.56
Sift
Benign
0.036
D
Sift4G
Benign
0.24
T
Polyphen
0.60
P
Vest4
0.65
MutPred
0.23
Loss of catalytic residue at H491 (P = 0.1007);
MVP
0.87
MPC
0.77
ClinPred
0.42
T
GERP RS
-6.2
Varity_R
0.17
gMVP
0.56
Mutation Taster
=26/74
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs145422660; hg19: chr7-120385839; API