rs199473537

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1PM2PM5PP2PP3_Moderate

The NM_000238.4(KCNH2):​c.2452T>G​(p.Ser818Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,614,074 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. S818P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

8
7
5

Clinical Significance

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

Conservation

PhyloP100: 7.37

Publications

5 publications found
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]
KCNH2 Gene-Disease associations (from GenCC):
  • long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 2
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
  • short QT syndrome
    Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
  • short QT syndrome type 1
    Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
  • Brugada syndrome
    Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000238.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-150948995-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2773436.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.4846 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.869

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2452T>G p.Ser818Ala missense_variant Exon 10 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.2452T>G p.Ser818Ala missense_variant Exon 10 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152184
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.00000398
AC:
1
AN:
251440
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461890
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727248
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
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:
0.00
AC:
0
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:
8.99e-7
AC:
1
AN:
1112008
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152184
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41448
American (AMR)
AF:
0.0000654
AC:
1
AN:
15282
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
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:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

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

Submissions by phenotype

Long QT syndrome Uncertain:2
Jan 12, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine, which is neutral and polar, with alanine, which is neutral and non-polar, at codon 818 of the KCNH2 protein (p.Ser818Ala). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 3071694). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. This variant disrupts the p.Ser818 amino acid residue in KCNH2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10086971, 10996323, 16432067, 23158531, 23303164, 26669661). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Jun 28, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.16
CardioboostArm
Benign
0.045
BayesDel_addAF
Pathogenic
0.32
D
BayesDel_noAF
Pathogenic
0.22
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.91
.;D
Eigen
Uncertain
0.30
Eigen_PC
Uncertain
0.30
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.88
D;D
M_CAP
Pathogenic
0.49
D
MetaRNN
Pathogenic
0.87
D;D
MetaSVM
Pathogenic
0.84
D
MutationAssessor
Uncertain
2.2
.;M
PhyloP100
7.4
PrimateAI
Pathogenic
0.80
T
PROVEAN
Uncertain
-2.4
N;N
REVEL
Pathogenic
0.75
Sift
Benign
0.14
T;T
Sift4G
Benign
0.093
T;T
Polyphen
0.26
B;P
Vest4
0.87
MutPred
0.60
.;Loss of disorder (P = 0.0619);
MVP
0.97
MPC
1.3
ClinPred
0.79
D
GERP RS
2.7
Varity_R
0.27
gMVP
0.89
Mutation Taster
=29/71
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: rs199473537; hg19: chr7-150646084; API