rs397515478

Positions:

• chr1-111787044-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_001378969.1(KCND3):​c.1169G>A​(p.Ser390Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: KCND3 NM_001378969.1 missense
• Clinical Significance: Conflicting classifications of pathogenicity no assertion criteria provided P:1 U:1
• Conservation: PhyloP100: 7.91

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 1 uncertain in NM_001378969.1
• 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, 0.904

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCND3	NM_001378969.1	c.1169G>A	p.Ser390Asn	missense_variant	3/8	ENST00000302127.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCND3	ENST00000302127.5	c.1169G>A	p.Ser390Asn	missense_variant	3/8	5	NM_001378969.1	P3
KCND3	ENST00000315987.6	c.1169G>A	p.Ser390Asn	missense_variant	3/8	1		P3
KCND3	ENST00000369697.5	c.1169G>A	p.Ser390Asn	missense_variant	2/6	1		A1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: no assertion criteria provided

Submissions by phenotype

Spinocerebellar ataxia type 19/22 Pathogenic:1

Pathogenic, no assertion criteria provided

research

O&I group, Department of Genetics, University Medical Center of Groningen

Jul 22, 2021

- -

Variant of unknown significance Uncertain:1

Uncertain significance, no assertion criteria provided

literature only

OMIM

Dec 01, 2012

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	.;D;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	.;D;D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.90	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-2.4	N;N;N
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.0090	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.75
MutPred		0.61		Gain of helix (P = 0.132);Gain of helix (P = 0.132);Gain of helix (P = 0.132);
MVP		0.96
MPC		2.0
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.90
gMVP		0.98

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: rs397515478; hg19: chr1-112329666;