11-74457425-G-C

Variant names:

• chr11-74457425-G-C
• rs17215444
• NM_005472.5:c.139C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_005472.5(KCNE3):​c.139C>G​(p.Arg47Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,706 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R47Q) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNE3 NM_005472.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.23
• Publications: 3 publications found

Genes affected

KCNE3 (HGNC:6243): (potassium voltage-gated channel subfamily E regulatory subunit 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. This gene encodes a member of the potassium channel, voltage-gated, isk-related subfamily. This member is a type I membrane protein, and a beta subunit that assembles with a potassium channel alpha-subunit to modulate the gating kinetics and enhance stability of the multimeric complex. This gene is prominently expressed in the kidney. A missense mutation in this gene is associated with hypokalemic periodic paralysis. [provided by RefSeq, Jul 2008]

KCNE3 Gene-Disease associations (from GenCC):

• Brugada syndrome 6

  Inheritance: AD, Unknown Classification: LIMITED, NO_KNOWN Submitted by: Ambry Genetics, Genomics England PanelApp, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)
• Brugada syndrome

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ENSG00000254928 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10181722).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNE3	NM_005472.5	c.139C>G	p.Arg47Gly	missense_variant	Exon 3 of 3	ENST00000310128.9	NP_005463.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNE3	ENST00000310128.9	c.139C>G	p.Arg47Gly	missense_variant	Exon 3 of 3	1	NM_005472.5	ENSP00000310557.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461492 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726984

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86242

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111698

Other (OTH) AF: 0.00 AC: 0 AN: 60370

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152214 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74352

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000241 AC: 1 AN: 41460

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: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Nov 03, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R47G variant (also known as c.139C>G), located in coding exon 1 of the KCNE3 gene, results from a C to G substitution at nucleotide position 139. The arginine at codon 47 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is poorly 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. -

Brugada syndrome 6 Uncertain:1

Dec 04, 2022

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. 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. This variant has not been reported in the literature in individuals affected with KCNE3-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 47 of the KCNE3 protein (p.Arg47Gly). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Uncertain	0.047	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	13
DANN	Benign	0.92
DEOGEN2	Benign	0.20	T;T;.;.;.
Eigen	Benign	-0.94
Eigen_PC	Benign	-0.90
FATHMM_MKL	Benign	0.24	N
LIST_S2	Benign	0.68	.;T;T;T;T
M_CAP	Benign	0.067	D
MetaRNN	Benign	0.10	T;T;T;T;T
MetaSVM	Benign	-0.29	T
MutationAssessor	Benign	1.2	L;L;.;.;.
PhyloP100		1.2
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.14	N;N;N;D;D
REVEL	Benign	0.16
Sift	Benign	0.072	T;T;T;D;D
Sift4G	Benign	0.39	T;T;.;.;.
Polyphen		0.023	B;B;.;.;.
Vest4		0.12
MutPred		0.22		Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);Loss of sheet (P = 0.0457);
MVP		0.92
MPC		0.20
ClinPred		0.10	T
GERP RS		4.0
Varity_R		0.068
gMVP		0.72
Mutation Taster		=92/8	polymorphism

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

Other links and lift over

dbSNP: rs17215444; hg19: chr11-74168470;