rs199473432

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PM5PP2PP3

The NM_000238.4(KCNH2):​c.2660G>T​(p.Arg887Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000072 in 1,389,090 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. R887H) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 7.2e-7 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

6
7
7

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.36

Publications

8 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 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-150948476-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 67423.
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, 0.784

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.2660G>T p.Arg887Leu missense_variant Exon 11 of 15 ENST00000262186.10 NP_000229.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.2660G>T p.Arg887Leu missense_variant Exon 11 of 15 1 NM_000238.4 ENSP00000262186.5

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD4 exome
AF:
7.20e-7
AC:
1
AN:
1389090
Hom.:
0
Cov.:
37
AF XY:
0.00000145
AC XY:
1
AN XY:
691360
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
31132
American (AMR)
AF:
0.00
AC:
0
AN:
42618
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
23504
East Asian (EAS)
AF:
0.00
AC:
0
AN:
32758
South Asian (SAS)
AF:
0.0000117
AC:
1
AN:
85654
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
42160
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5436
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1070240
Other (OTH)
AF:
0.00
AC:
0
AN:
55588
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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
Cov.:
31

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Cardiac arrhythmia Uncertain:1
Aug 08, 2019
Color Diagnostics, LLC DBA Color Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant of Uncertain Significance due to insufficient evidence: This missense variant is located in the cytoplasmic domain of the KCNH2 protein. Computational prediction tools and conservation analyses suggest that this variant may impact the protein function. Computational splicing tools suggest that this variant may not impact the RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the pathogenicity of this variant conclusively. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.49
CardioboostArm
Benign
0.039
BayesDel_addAF
Pathogenic
0.44
D
BayesDel_noAF
Pathogenic
0.40
CADD
Benign
21
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
.;D
Eigen
Benign
0.11
Eigen_PC
Benign
0.13
FATHMM_MKL
Uncertain
0.94
D
LIST_S2
Uncertain
0.91
D;D
M_CAP
Pathogenic
0.88
D
MetaRNN
Pathogenic
0.78
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Benign
1.8
.;L
PhyloP100
4.4
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-3.5
D;D
REVEL
Pathogenic
0.76
Sift
Benign
0.13
T;T
Sift4G
Benign
0.14
T;T
Polyphen
0.055
B;B
Vest4
0.59
MutPred
0.55
.;Gain of loop (P = 0.0045);
MVP
0.99
MPC
0.25
ClinPred
0.99
D
GERP RS
4.1
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.41
gMVP
0.89
Mutation Taster
=5/95
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: rs199473432; hg19: chr7-150645564; API