chr7-150955442-C-T

Variant summary

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

The ENST00000330883.9(KCNH2):​c.62G>A​(p.Gly21Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000141 in 1,413,506 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: not found (cov: 34)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

KCNH2
ENST00000330883.9 missense

Scores

1
4
11

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.74

Publications

0 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: 2.8194 (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=0.20794892).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNH2NM_000238.4 linkc.1128+1849G>A intron_variant Intron 5 of 14 ENST00000262186.10 NP_000229.1 Q12809-1Q15BH2A0A090N8Q0

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkc.1128+1849G>A intron_variant Intron 5 of 14 1 NM_000238.4 ENSP00000262186.5 Q12809-1

Frequencies

GnomAD3 genomes
Cov.:
34
GnomAD2 exomes
AF:
0.0000118
AC:
2
AN:
169682
AF XY:
0.0000109
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000726
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000141
AC:
2
AN:
1413506
Hom.:
0
Cov.:
31
AF XY:
0.00000143
AC XY:
1
AN XY:
698904
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32140
American (AMR)
AF:
0.0000517
AC:
2
AN:
38666
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25294
East Asian (EAS)
AF:
0.00
AC:
0
AN:
36684
South Asian (SAS)
AF:
0.00
AC:
0
AN:
80130
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
48852
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5116
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1088192
Other (OTH)
AF:
0.00
AC:
0
AN:
58432
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
34
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

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

Submissions by phenotype

Long QT syndrome Uncertain:1
Dec 24, 2017
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has been reported in an individual affected with Long QT syndrome, although a definitive diagnosis was not possible (PMID: 26189708). This sequence change replaces glycine with aspartic acid at codon 62 of the KCNH2 protein (p.Gly21Asp). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and aspartic acid. The KCNH2 gene has multiple clinically relevant transcripts. The p.Gly21Asp variant occurs in alternate transcript NM_172057.2, which corresponds to position c.1128+1849G>A in NM_000238.3, the primary transcript listed in the Methods. 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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Uncertain
0.12
D
BayesDel_noAF
Uncertain
-0.070
CADD
Benign
20
DANN
Benign
0.95
Eigen
Benign
-0.15
Eigen_PC
Benign
-0.0084
FATHMM_MKL
Benign
0.70
D
LIST_S2
Benign
0.55
T
M_CAP
Pathogenic
0.32
D
MetaRNN
Benign
0.21
T
MetaSVM
Uncertain
0.48
D
PhyloP100
1.7
PROVEAN
Benign
1.3
N
REVEL
Uncertain
0.30
Sift
Benign
0.66
T
Sift4G
Benign
0.42
T
Polyphen
0.80
P
Vest4
0.17
MutPred
0.27
Loss of helix (P = 0.0376);
MVP
0.56
ClinPred
0.11
T
GERP RS
4.1
PromoterAI
0.0058
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Mutation Taster
=85/15
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.10
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: rs1167016668; hg19: chr7-150652530; API