rs989191027

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 1P and 3B. PP2BP4_ModerateBS2_Supporting

The NM_000238.4(KCNH2):​c.682G>C​(p.Ala228Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000545 in 1,466,674 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/23 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. A228V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000040 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000015 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

2
3
14

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

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: Likely_benign. The variant received -2 ACMG points.

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=0.23228768).
BS2
High AC in GnomAd4 at 6 AD 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.682G>C p.Ala228Pro missense_variant Exon 4 of 15 ENST00000262186.10 NP_000229.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.682G>C p.Ala228Pro missense_variant Exon 4 of 15 1 NM_000238.4 ENSP00000262186.5

Frequencies

GnomAD3 genomes
AF:
0.0000395
AC:
6
AN:
151852
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000121
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:
0.000479
GnomAD4 exome
AF:
0.00000152
AC:
2
AN:
1314822
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
649004
show subpopulations
African (AFR)
AF:
0.0000745
AC:
2
AN:
26850
American (AMR)
AF:
0.00
AC:
0
AN:
26910
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
22878
East Asian (EAS)
AF:
0.00
AC:
0
AN:
28288
South Asian (SAS)
AF:
0.00
AC:
0
AN:
72174
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
32910
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4356
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1046164
Other (OTH)
AF:
0.00
AC:
0
AN:
54292
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
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:
0.0000395
AC:
6
AN:
151852
Hom.:
0
Cov.:
33
AF XY:
0.0000539
AC XY:
4
AN XY:
74162
show subpopulations
African (AFR)
AF:
0.000121
AC:
5
AN:
41420
American (AMR)
AF:
0.00
AC:
0
AN:
15232
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10478
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67910
Other (OTH)
AF:
0.000479
AC:
1
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.567
Heterozygous variant carriers
0
1
2
3
4
5
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:
0.00
Hom.:
0
Bravo
AF:
0.0000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Uncertain:1
Nov 19, 2024
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Has not been previously published as pathogenic or benign to our knowledge; In silico analysis indicates that this missense variant does not alter protein structure/function

Long QT syndrome Uncertain:1
Jan 01, 2025
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 proline, which is neutral and non-polar, at codon 228 of the KCNH2 protein (p.Ala228Pro). This variant is present in population databases (no rsID available, gnomAD 0.02%). 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: 526974). 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.

Cardiovascular phenotype Uncertain:1
Aug 08, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A228P variant (also known as c.682G>C), located in coding exon 4 of the KCNH2 gene, results from a G to C substitution at nucleotide position 682. The alanine at codon 228 is replaced by proline, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Short QT syndrome type 1;C3150943:Long QT syndrome 2 Uncertain:1
Sep 20, 2021
Fulgent Genetics, Fulgent Genetics
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
0.069
CardioboostArm
Benign
0.00018
BayesDel_addAF
Uncertain
0.045
T
BayesDel_noAF
Benign
-0.17
CADD
Benign
13
DANN
Benign
0.97
DEOGEN2
Benign
0.34
T;T
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.12
N
LIST_S2
Benign
0.64
T;T
M_CAP
Pathogenic
0.94
D
MetaRNN
Benign
0.23
T;T
MetaSVM
Uncertain
0.30
D
MutationAssessor
Benign
0.69
N;.
PhyloP100
0.027
PrimateAI
Pathogenic
0.86
D
PROVEAN
Benign
-0.54
N;.
REVEL
Uncertain
0.37
Sift
Benign
0.11
T;.
Sift4G
Benign
0.29
T;T
Vest4
0.12
ClinPred
0.051
T
GERP RS
0.59
Varity_R
0.089
gMVP
0.51
Mutation Taster
=81/19
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: rs989191027; hg19: chr7-150655381; API