rs199473504

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBS2_Supporting

The NM_000238.4(KCNH2):​c.940G>A​(p.Gly314Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000496 in 1,613,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

1
5
13

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2O:1

Conservation

PhyloP100: 0.663
Variant links:
Genes affected
KCNH2 (HGNC:6251): (potassium voltage-gated channel subfamily H member 2) This gene encodes a component of a voltage-activated potassium channel found in cardiac muscle, nerve cells, and microglia. Four copies of this protein interact with one copy of the KCNE2 protein to form a functional potassium channel. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, May 2022]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.12590757).
BS2
High AC in GnomAdExome4 at 5 AD,Digenic gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.940G>A p.Gly314Ser missense_variant Exon 5 of 15 ENST00000262186.10 NP_000229.1 Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.940G>A p.Gly314Ser missense_variant Exon 5 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1
KCNH2ENST00000532957.5 linkn.1163G>A non_coding_transcript_exon_variant Exon 5 of 9 2
KCNH2ENST00000684241.1 linkn.1773G>A non_coding_transcript_exon_variant Exon 3 of 13

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152222
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000399
AC:
1
AN:
250406
Hom.:
0
AF XY:
0.00000737
AC XY:
1
AN XY:
135620
show subpopulations
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:
0.00000885
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461498
Hom.:
0
Cov.:
32
AF XY:
0.00000275
AC XY:
2
AN XY:
727064
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000270
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152222
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74370
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000207
Gnomad4 FIN
AF:
0.0000941
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Nov 30, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Aug 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 314 of the KCNH2 protein (p.Gly314Ser). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with referral for the Long QT syndrome clinical genetic test. (PMID: 19716085). ClinVar contains an entry for this variant (Variation ID: 67548). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The serine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Experimental studies have shown that this missense change does not substantially affect KCNH2 function (PMID: 31493592). 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. -

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
0.064
BayesDel_addAF
Pathogenic
0.21
D
BayesDel_noAF
Uncertain
0.070
CADD
Benign
22
DANN
Benign
0.81
DEOGEN2
Benign
0.31
T;T
Eigen
Benign
-0.74
Eigen_PC
Benign
-0.53
FATHMM_MKL
Benign
0.59
D
LIST_S2
Benign
0.74
T;T
M_CAP
Uncertain
0.15
D
MetaRNN
Benign
0.13
T;T
MetaSVM
Uncertain
-0.20
T
MutationAssessor
Benign
-1.8
N;.
PrimateAI
Uncertain
0.75
T
PROVEAN
Benign
-0.080
N;.
REVEL
Uncertain
0.52
Sift
Benign
1.0
T;.
Sift4G
Benign
1.0
T;T
Polyphen
0.0010
B;.
Vest4
0.19
MutPred
0.77
Gain of phosphorylation at G314 (P = 0.0129);.;
MVP
0.99
MPC
1.0
ClinPred
0.061
T
GERP RS
2.6
Varity_R
0.051
gMVP
0.57

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs199473504; hg19: chr7-150654567; COSMIC: COSV51129285; COSMIC: COSV51129285; API