rs1217571134

Positions:

• chr1-111982281-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001378969.1(KCND3):​c.446A>G​(p.Asp149Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,876 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 Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCND3 NM_001378969.1 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.67

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCND3. . Gene score misZ 3.8545 (greater than the threshold 3.09). Trascript score misZ 4.8782 (greater than threshold 3.09). GenCC has associacion of gene with spinocerebellar ataxia type 19/22, Brugada syndrome 1, Brugada syndrome 9.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.798

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCND3	NM_001378969.1	c.446A>G	p.Asp149Gly	missense_variant	2/8	ENST00000302127.5	NP_001365898.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCND3	ENST00000302127.5	c.446A>G	p.Asp149Gly	missense_variant	2/8	5	NM_001378969.1	ENSP00000306923	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251310 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135886

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461876 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Nov 08, 2016

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

AiLife Diagnostics, AiLife Diagnostics

Jul 28, 2021

- -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 14, 2023

The p.D149G variant (also known as c.446A>G), located in coding exon 1 of the KCND3 gene, results from an A to G substitution at nucleotide position 446. The aspartic acid at codon 149 is replaced by glycine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Spinocerebellar ataxia type 19/22 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 05, 2020

This sequence change replaces aspartic acid with glycine at codon 149 of the KCND3 protein (p.Asp149Gly). The aspartic acid residue is highly conserved and there is a moderate physicochemical difference between aspartic acid and glycine. 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). This variant has not been reported in the literature in individuals with KCND3-related conditions. ClinVar contains an entry for this variant (Variation ID: 447628). This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.87
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Uncertain	25
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.55	.;D;.
Eigen	Uncertain	0.26
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.88	.;D;D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.80	D;D;D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Uncertain	2.8	M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-4.2	D;D;D
REVEL	Pathogenic	0.79
Sift	Uncertain	0.028	D;D;D
Sift4G	Uncertain	0.041	D;D;D
Polyphen		0.013	.;B;.
Vest4		0.79
MutPred		0.30		Loss of stability (P = 0.025);Loss of stability (P = 0.025);Loss of stability (P = 0.025);
MVP		0.98
MPC		1.8
ClinPred		0.93	D
GERP RS		5.6
Varity_R		0.55
gMVP		0.83

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

Other links and lift over

dbSNP: rs1217571134; hg19: chr1-112524903;