rs748762712

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2PP2BP4_Moderate

The NM_000238.4(KCNH2):​c.731C>T​(p.Ala244Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000142 in 1,405,146 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/23 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. A244T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 8.0e-7 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

2
1
17

Clinical Significance

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

Conservation

PhyloP100: 0.0270

Publications

3 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: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
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.
BP4
Computational evidence support a benign effect (MetaRNN=0.14137071).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.731C>T p.Ala244Val missense_variant Exon 4 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.731C>T p.Ala244Val missense_variant Exon 4 of 15 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
AF:
0.00000659
AC:
1
AN:
151804
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
7.98e-7
AC:
1
AN:
1253342
Hom.:
0
Cov.:
32
AF XY:
0.00000163
AC XY:
1
AN XY:
614496
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:
25434
American (AMR)
AF:
0.00
AC:
0
AN:
19098
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
20142
East Asian (EAS)
AF:
0.00
AC:
0
AN:
27136
South Asian (SAS)
AF:
0.00
AC:
0
AN:
60254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
31018
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3742
European-Non Finnish (NFE)
AF:
9.85e-7
AC:
1
AN:
1015078
Other (OTH)
AF:
0.00
AC:
0
AN:
51440
⚠️ 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: 0.225
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:
0.00000659
AC:
1
AN:
151804
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74164
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000242
AC:
1
AN:
41400
American (AMR)
AF:
0.00
AC:
0
AN:
15230
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10476
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67888
Other (OTH)
AF:
0.00
AC:
0
AN:
2082
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 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
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
LINK: link

Submissions by phenotype

not provided Uncertain:1
Apr 06, 2021
Revvity Omics, Revvity
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Long QT syndrome Uncertain:1
Dec 24, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 244 of the KCNH2 protein (p.Ala244Val). This variant is not present in population databases (gnomAD no frequency). 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: 405349). 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.070
CardioboostArm
Benign
0.000028
BayesDel_addAF
Benign
0.0041
T
BayesDel_noAF
Benign
-0.23
CADD
Benign
13
DANN
Benign
0.89
DEOGEN2
Benign
0.32
T;T
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.3
FATHMM_MKL
Benign
0.020
N
LIST_S2
Benign
0.23
T;T
M_CAP
Pathogenic
0.88
D
MetaRNN
Benign
0.14
T;T
MetaSVM
Uncertain
-0.032
T
MutationAssessor
Benign
0.20
N;.
PhyloP100
0.027
PrimateAI
Pathogenic
0.81
D
PROVEAN
Benign
0.040
N;.
REVEL
Benign
0.26
Sift
Benign
0.74
T;.
Sift4G
Benign
0.53
T;T
Polyphen
0.0
B;.
Vest4
0.073
MutPred
0.16
Loss of loop (P = 0.0603);.;
MVP
0.55
MPC
1.0
ClinPred
0.026
T
GERP RS
-1.8
Varity_R
0.024
gMVP
0.39
Mutation Taster
=92/8
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs748762712; hg19: chr7-150655332; COSMIC: COSV51238041; COSMIC: COSV51238041; API