rs730880117

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_ModerateBS2

The NM_000238.4(KCNH2):​c.755G>A​(p.Arg252Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000175 in 1,371,402 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: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000017 ( 0 hom. )

Consequence

KCNH2
NM_000238.4 missense

Scores

3
3
13

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 0.275
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.23400828).
BS2
High AC in GnomAdExome4 at 21 AD,Digenic gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNH2NM_000238.4 linkuse as main transcriptc.755G>A p.Arg252Gln missense_variant 4/15 ENST00000262186.10 NP_000229.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNH2ENST00000262186.10 linkuse as main transcriptc.755G>A p.Arg252Gln missense_variant 4/151 NM_000238.4 ENSP00000262186 P1Q12809-1
KCNH2ENST00000532957.5 linkuse as main transcriptn.978G>A non_coding_transcript_exon_variant 4/92
KCNH2ENST00000684241.1 linkuse as main transcriptn.1588G>A non_coding_transcript_exon_variant 2/13

Frequencies

GnomAD3 genomes
AF:
0.0000198
AC:
3
AN:
151842
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000299
AC:
1
AN:
33492
Hom.:
0
AF XY:
0.0000501
AC XY:
1
AN XY:
19944
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.000960
GnomAD4 exome
AF:
0.0000172
AC:
21
AN:
1219560
Hom.:
0
Cov.:
32
AF XY:
0.0000202
AC XY:
12
AN XY:
594622
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000646
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.0000335
Gnomad4 NFE exome
AF:
0.0000190
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000198
AC:
3
AN:
151842
Hom.:
0
Cov.:
33
AF XY:
0.0000270
AC XY:
2
AN XY:
74178
show subpopulations
Gnomad4 AFR
AF:
0.0000483
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000151

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 18, 2023This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 252 of the KCNH2 protein (p.Arg252Gln). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 180380). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -
Uncertain significance, no assertion criteria providedclinical testingBlueprint GeneticsMay 26, 2014- -
Short QT syndrome type 1 Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingClinical Genomics Laboratory, Stanford MedicineJul 02, 2021The p.Arg252Gln variant in the KCNH2gene has not been previously reported in association with disease.This variant has been identified in 2/64,380 chromosomes by the Genome Aggregation Database (http://gnomad.broadinstitute.org/).Notably, this region is indicated to have low coverage.The arginine at position 252 is poorly evolutionarily conserved and severalspecies have a glutamine at this position.Computational tools predict that the p.Arg252Gln variant is deleterious; however, the accuracy of in silicoalgorithms is limited.These data were assessed using the ACMG/AMP variant interpretation guidelines. In summary, the significance of thep.Arg252Glnvariant is uncertain. Additional information is needed to resolve the significance of this variant. [ACMG evidence codes used: PP3] -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.083
BayesDel_addAF
Pathogenic
0.18
D
BayesDel_noAF
Uncertain
0.020
CADD
Benign
17
DANN
Benign
0.95
DEOGEN2
Benign
0.38
T;T
Eigen
Benign
-0.88
Eigen_PC
Benign
-0.95
FATHMM_MKL
Benign
0.035
N
LIST_S2
Benign
0.75
T;T
M_CAP
Pathogenic
0.85
D
MetaRNN
Benign
0.23
T;T
MetaSVM
Uncertain
0.41
D
MutationAssessor
Benign
0.69
N;.
MutationTaster
Benign
1.0
N;N;N
PrimateAI
Pathogenic
0.85
D
PROVEAN
Benign
-0.96
N;.
REVEL
Uncertain
0.59
Sift
Benign
0.63
T;.
Sift4G
Benign
0.19
T;T
Polyphen
0.29
B;.
Vest4
0.082
MutPred
0.49
Loss of methylation at R252 (P = 0.0085);.;
MVP
0.97
MPC
1.6
ClinPred
0.057
T
GERP RS
1.3
Varity_R
0.026
gMVP
0.41

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs730880117; hg19: chr7-150655308; API