rs148968498

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP6BS2

The NM_172201.2(KCNE2):​c.80G>A​(p.Arg27His) variant causes a missense change. The variant allele was found at a frequency of 0.0000446 in 1,614,144 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R27C) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.00023 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000025 ( 0 hom. )

Consequence

KCNE2
NM_172201.2 missense

Scores

4
7
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2O:1

Conservation

PhyloP100: 4.64

Publications

6 publications found
Variant links:
Genes affected
KCNE2 (HGNC:6242): (potassium voltage-gated channel subfamily E regulatory subunit 2) 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 small integral membrane subunit that assembles with the KCNH2 gene product, a pore-forming protein, to alter its function. This gene is expressed in heart and muscle and the gene mutations are associated with cardiac arrhythmia. [provided by RefSeq, Jul 2008]
KCNE2 Gene-Disease associations (from GenCC):
  • familial atrial fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • long QT syndrome 6
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
  • long QT syndrome
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

BP6
Variant 21-34370558-G-A is Benign according to our data. Variant chr21-34370558-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 67623.
BS2
High AC in GnomAd4 at 35 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNE2NM_172201.2 linkc.80G>A p.Arg27His missense_variant Exon 2 of 2 ENST00000290310.4 NP_751951.1 Q9Y6J6
LOC105372791NR_188571.1 linkn.729C>T non_coding_transcript_exon_variant Exon 2 of 3
LOC105372791NR_188572.1 linkn.729C>T non_coding_transcript_exon_variant Exon 2 of 2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNE2ENST00000290310.4 linkc.80G>A p.Arg27His missense_variant Exon 2 of 2 1 NM_172201.2 ENSP00000290310.2 Q9Y6J6

Frequencies

GnomAD3 genomes
AF:
0.000230
AC:
35
AN:
152136
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.000797
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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
GnomAD2 exomes
AF:
0.0000636
AC:
16
AN:
251474
AF XY:
0.0000368
show subpopulations
Gnomad AFR exome
AF:
0.000738
Gnomad AMR exome
AF:
0.0000867
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000253
AC:
37
AN:
1461890
Hom.:
0
Cov.:
31
AF XY:
0.0000261
AC XY:
19
AN XY:
727246
show subpopulations
African (AFR)
AF:
0.000657
AC:
22
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000719
AC:
8
AN:
1112008
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
AF:
0.000230
AC:
35
AN:
152254
Hom.:
0
Cov.:
32
AF XY:
0.000161
AC XY:
12
AN XY:
74442
show subpopulations
African (AFR)
AF:
0.000794
AC:
33
AN:
41544
American (AMR)
AF:
0.000131
AC:
2
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
292
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.511
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000667
Hom.:
0
Bravo
AF:
0.000283
ESP6500AA
AF:
0.000227
AC:
1
ESP6500EA
AF:
0.00
AC:
0
ExAC
AF:
0.0000824
AC:
10
Asia WGS
AF:
0.000289
AC:
1
AN:
3478

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:3Benign:2Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Atrial fibrillation, familial, 4;C3150953:Long QT syndrome 6 Uncertain:1
Oct 05, 2021
New York Genome Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Apr 21, 2017
Stanford Center for Inherited Cardiovascular Disease, Stanford University
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:provider interpretation

This variant was found in a 14 yo male with a history of V-fib cardiac arrest, WPW, atrial fibrillation, and LVNC found on cardiac MRI. He had genetic testing with the Invitae laboratory. The following 124 genes associated with heritable arrhythmia syndromes and cardiomyopathies were evaluated for sequence changes and exonic deletions/duplications: ABCC9, ACADVL, ACTC1, ACTN2, AGL, AKAP9, ALMS1, ANK2, ANKRD1, BAG3, CACNA1C, CACNA2D1, CACNB2, CALM1, CALM2, CALM3, CALR3, CASQ2, CAV1, CAV3, CHRM2, CPT2, CRYAB, CSRP3, CTF1, CTNNA3, DES, DMD, DNAJC19, DOLK, DSC2, DSG2, DSP, DTNA, ELAC2, EMD, EYA4, FHL1, FHL2, FKRP, FKTN, FLNC, GAA, GATA4, GATA6, GATAD1, GJA1, GJA5, GLA, GPD1L, HCN4, ILK, JPH2, JUP, KCNA5, KCND3, KCNE1, KCNE2, KCNE3, KCNE5, KCNH2, KCNJ2, KCNJ5, KCNJ8, KCNK3, KCNQ1, LAMA4, LAMP2, LDB3, LMNA, LRRC10, MTO1, MYBPC3, MYH6, MYH7, MYL2, MYL3, MYL4, MYLK2, MYOM1, MYOZ2, MYPN, NEBL, NEXN, NKX2-5, NKX2-6, NPPA, PDLIM3, PKP2, PLEKHM2, PLN, PRDM16, PRKAG2, RAF1, RANGRF, RBM20, RYR2, SCN10A, SCN1B, SCN2B, SCN3B, SCN4B, SCN5A, SGCD, SLC22A5, SLMAP, SNTA1, TAZ, TBX5, TCAP, TGFB3, TMEM43, TMEM70, TMPO, TNNC1, TNNI3, TNNT2, TPM1, TRDN, TRPM4, TTN, TTR, TXNRD2, VCL. The following gene was evaluated for sequence changes only: SDHA. One variant was reported: p.Arg27His (R27H; c.80G>A) in exon 2 of the KCNE2 gene (NM_172201.1; ENST00000290310) Chromosome location: 21:35742857 G / A Based on the information reviewed below, including its appreciable frequency in the broader population, particularly in people with African ancestry such as our patient, we classify it as a Variant of Uncertain Significance (VUS), probably benign, concluding that there is not sufficient evidence for its pathogenicity to warrant using it for diagnosis or predictive genetic testing. This variant has previously been reported in two individuals suspected to have LQTS. Their ethnicity is not reported. There is no published segregation data. The variant was reported in 1 individual in the Familion compendium, which includes 2500 patients referred for clinical long QT genetic testing (Kapplinger et al 2009, PMID: 19716085). Of note, there is no phenotype data on this cohort confirming a diagnosis of LQTS, and genetic testing had a low yield of 36% (vs. 70% in cohorts with firm diagnoses of long QT). There is also a lack of clarity regarding which variants were seen alongside another variant (9% of the cohort had multiple variants). The Arg27His variant was also reported by Sauer and Marc-Aurele (2016) in a 19-day-old female neonate with documented VF and a QTc of 465 msec; the baby also had a second variant in KCNE2, Ile20Asn (which is absent from gnomAD and not yet reported to ClinVar by any genetic testing lab), apparently in trans—given that her mother tested positive only for Arg27His (PMID: 27465075). Her testing was done at Familion. This is a conservative amino acid change, resulting in the replacement of a positively-charged Arginine with a positively-charged Histidine. Arginine at this location is fairly highly conserved across ~100 vertebrate species, although Histidine is the default amino acid in at least 2 species, suggesting that this missense change is tolerated (in two other species it is a Serine or a Glutamine). There are no missense variants at nearby residues (+/- 10) currently listed in ClinVar as Likely Pathogenic or Pathogenic. According to the Invitae report, algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C25". These predictions have not been confirmed by published functional studies. This variant was reported online in 24 individuals in the gnomAD database, which includes variant calls on ~140,000 individuals of European, African, Latino, South Asian, Ashkenazi, and East Asian descent. Specifically, the variant was observed in 20/12,012 individuals with African ancestry like our patient ( -

Long QT syndrome Uncertain:1
Jun 01, 2014
CSER _CC_NCGL, University of Washington
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:research

- -

Long QT syndrome 6 Benign:1
Oct 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Cardiovascular phenotype Benign:1
Oct 13, 2023
Ambry Genetics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Congenital long QT syndrome Other:1
-
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19716085). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.080
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Pathogenic
0.34
CADD
Benign
20
DANN
Uncertain
1.0
DEOGEN2
Benign
0.39
T
Eigen
Uncertain
0.59
Eigen_PC
Uncertain
0.55
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Benign
0.69
T
M_CAP
Uncertain
0.11
D
MetaRNN
Uncertain
0.59
D
MetaSVM
Pathogenic
0.85
D
MutationAssessor
Benign
1.7
L
PhyloP100
4.6
PrimateAI
Benign
0.34
T
PROVEAN
Benign
-1.4
N
REVEL
Pathogenic
0.76
Sift
Benign
0.037
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.67
MVP
0.96
MPC
0.16
ClinPred
0.081
T
GERP RS
5.5
Varity_R
0.12
gMVP
0.87
Mutation Taster
=14/86
disease causing

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

Other links and lift over

dbSNP: rs148968498; hg19: chr21-35742857; API