chr1-111776196-T-C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 1P and 6B. PP2BP4_ModerateBS2

The NM_001378969.1(KCND3):c.1849A>G(p.Ile617Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000383 in 1,461,886 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 (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

KCND3
NM_001378969.1 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 3.04

Publications

1 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

KCND3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

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.

BP4

Computational evidence support a benign effect (MetaRNN=0.21625903).

BS2

High AC in GnomAdExome4 at 56 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCND3	NM_001378969.1 link	c.1849A>G	p.Ile617Val	missense_variant	Exon 8 of 8	ENST00000302127.5	NP_001365898.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
KCND3	ENST00000302127.5 link	c.1849A>G	p.Ile617Val	missense_variant	Exon 8 of 8	5	NM_001378969.1	ENSP00000306923.4	Q9UK17-1
KCND3	ENST00000315987.6 link	c.1849A>G	p.Ile617Val	missense_variant	Exon 8 of 8	1		ENSP00000319591.2	Q9UK17-1
KCND3	ENST00000369697.5 link	c.1792A>G	p.Ile598Val	missense_variant	Exon 6 of 6	1		ENSP00000358711.1	Q9UK17-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000119

AC:

AN:

251324

AF XY:

0.00000736

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 FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000383

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.0000289

AC XY:

AN XY:

727248

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.0000495

AC:

AN:

1112010

Other (OTH)

AF:

0.0000166

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.462

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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.:

Alfa

AF:

0.0000508

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiovascular phenotype

Uncertain:1

May 26, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.I617V variant (also known as c.1849A>G), located in coding exon 7 of the KCND3 gene, results from an A to G substitution at nucleotide position 1849. The isoleucine at codon 617 is replaced by valine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Spinocerebellar ataxia type 19/22

Uncertain:1

Feb 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 617 of the KCND3 protein (p.Ile617Val). This variant is present in population databases (no rsID available, gnomAD 0.003%). 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 533723). This variant has not been reported in the literature in individuals affected with KCND3-related conditions. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.11

BayesDel_addAF

Uncertain

0.15

BayesDel_noAF

Uncertain

0.040

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Benign

0.32

.;T;.

Eigen

Uncertain

0.20

Eigen_PC

Uncertain

0.32

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.88

.;D;D

M_CAP

Benign

0.054

MetaRNN

Benign

0.22

T;T;T

MetaSVM

Uncertain

0.73

MutationAssessor

Benign

1.6

.;L;.

PhyloP100

3.0

PrimateAI

Pathogenic

0.82

PROVEAN

Benign

-0.30

N;N;N

REVEL

Uncertain

0.41

Sift

Uncertain

0.0070

D;D;D

Sift4G

Benign

0.36

T;T;T

Polyphen

0.50

.;P;.

Vest4

0.45

MutPred

0.22

.;Loss of sheet (P = 7e-04);.;

MVP

0.52

MPC

0.28

ClinPred

0.68

GERP RS

5.8

Varity_R

0.29

gMVP

0.42

Mutation Taster

=79/21

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over