1-111982638-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP2

The NM_001378969.1(KCND3):​c.89C>A​(p.Ala30Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,198 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

KCND3
NM_001378969.1 missense

Scores

4
9
6

Clinical Significance

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

Conservation

PhyloP100: 8.05

Publications

0 publications found
Variant links:
Genes affected
KCND3 (HGNC:6239): (potassium voltage-gated channel subfamily D member 3) 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 includes two isoforms with different sizes, which are encoded by alternatively spliced transcript variants of this gene. [provided by RefSeq, Jul 2008]
KCND3 Gene-Disease associations (from GenCC):
  • neurodevelopmental disorder
    Inheritance: AD Classification: STRONG Submitted by: G2P
  • spinocerebellar ataxia type 19/22
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet, Ambry Genetics
  • Brugada syndrome 9
    Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp
  • Brugada syndrome 1
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the KCND3 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 20 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Gene score misZ: 3.8545 (above the threshold of 3.09). Trascript score misZ: 4.8782 (above the threshold of 3.09). GenCC associations: The gene is linked to spinocerebellar ataxia type 19/22, neurodevelopmental disorder, Brugada syndrome 1, Brugada syndrome 9.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCND3NM_001378969.1 linkc.89C>A p.Ala30Asp missense_variant Exon 2 of 8 ENST00000302127.5 NP_001365898.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCND3ENST00000302127.5 linkc.89C>A p.Ala30Asp missense_variant Exon 2 of 8 5 NM_001378969.1 ENSP00000306923.4 Q9UK17-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152198
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152198
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74350
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5176
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68046
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
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

Genome 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
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Cardiovascular phenotype Uncertain:1
Mar 01, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.89C>A (p.A30D) alteration is located in exon 2 (coding exon 1) of the KCND3 gene. This alteration results from a C to A substitution at nucleotide position 89, causing the alanine (A) at amino acid position 30 to be replaced by an aspartic acid (D). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Spinocerebellar ataxia type 19/22 Uncertain:1
Nov 24, 2021
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. This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 30 of the KCND3 protein (p.Ala30Asp). This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with KCND3-related conditions. ClinVar contains an entry for this variant (Variation ID: 465169). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C35"). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.86
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.43
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Benign
0.36
.;T;.
Eigen
Uncertain
0.31
Eigen_PC
Uncertain
0.44
FATHMM_MKL
Uncertain
0.95
D
LIST_S2
Uncertain
0.96
.;D;D
M_CAP
Uncertain
0.17
D
MetaRNN
Uncertain
0.57
D;D;D
MetaSVM
Uncertain
0.54
D
MutationAssessor
Benign
1.0
L;L;L
PhyloP100
8.1
PrimateAI
Uncertain
0.71
T
PROVEAN
Benign
-1.7
N;N;N
REVEL
Pathogenic
0.76
Sift
Benign
0.096
T;T;T
Sift4G
Benign
0.52
T;T;T
Polyphen
0.50
.;P;.
Vest4
0.67
MutPred
0.40
Gain of solvent accessibility (P = 0.0354);Gain of solvent accessibility (P = 0.0354);Gain of solvent accessibility (P = 0.0354);
MVP
0.99
MPC
2.0
ClinPred
0.83
D
GERP RS
5.4
PromoterAI
-0.0089
Neutral
Varity_R
0.59
gMVP
0.92
Mutation Taster
=56/44
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs1307934269; hg19: chr1-112525260; API