1-110673407-C-A

Position:

• chr1-110673407-C-A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_002232.5(KCNA3):​c.1403G>T​(p.Gly468Val) 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. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G468F) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: KCNA3 NM_002232.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.90

Genes affected

KCNA3 (HGNC:6221): (potassium voltage-gated channel subfamily A member 3) Potassium 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, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, members of which allow nerve cells to efficiently repolarize following an action potential. It plays an essential role in T-cell proliferation and activation. This gene appears to be intronless and it is clustered together with KCNA2 and KCNA10 genes on chromosome 1. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a helix (size 18) in uniprot entity KCNA3_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_002232.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr1-110673407-CC-AA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2500317.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.966
• PP5: Variant 1-110673407-C-A is Pathogenic according to our data. Variant chr1-110673407-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3068740.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNA3	NM_002232.5	c.1403G>T	p.Gly468Val	missense_variant	1/1	ENST00000369769.4	NP_002223.3
KCNA3	NR_109845.2	n.48G>T		non_coding_transcript_exon_variant	1/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNA3	ENST00000369769.4	c.1403G>T	p.Gly468Val	missense_variant	1/1	6	NM_002232.5	ENSP00000358784.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

KCNA3-associated developmental and epileptic encephalopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

research

Institute of Human Genetics, University of Leipzig Medical Center

Nov 21, 2023

This variant was identified as de novo (maternity and paternity confirmed). Criteria applied: PS3, PS2_MOD, PM2_SUP, PP3 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Pathogenic	5.0	H
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-8.1	D
REVEL	Pathogenic	0.92
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.83		Gain of sheet (P = 0.1945);
MVP		0.93
ClinPred		1.0	D
GERP RS		5.9
Varity_R		0.97
gMVP		1.0

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-111216029;