rs120074183

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):​c.1034G>A​(p.Gly345Glu) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,830 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/25 in silico tools predict a damaging outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G345V) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense, splice_region

Scores

17
2
1
Splicing: ADA: 0.6518
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 9.33

Publications

17 publications found
Variant links:
Genes affected
KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]
KCNQ1 Gene-Disease associations (from GenCC):
  • long QT syndrome
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • long QT syndrome 1
    Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • Jervell and Lange-Nielsen syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
  • atrial fibrillation, familial, 3
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
  • short QT syndrome
    Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
  • short QT syndrome type 2
    Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
  • familial atrial fibrillation
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Jervell and Lange-Nielsen syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1
In a hotspot region, there are 24 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000218.3
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr11-2585213-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3338779.Status of the report is criteria_provided_single_submitter, 1 stars.
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 2, long QT syndrome 1, Jervell and Lange-Nielsen syndrome 1, long QT syndrome, short QT syndrome, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy, familial atrial fibrillation, atrial fibrillation, familial, 3.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.992
PP5
Variant 11-2585213-G-A is Pathogenic according to our data. Variant chr11-2585213-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 3122.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ1NM_000218.3 linkc.1034G>A p.Gly345Glu missense_variant, splice_region_variant Exon 8 of 16 ENST00000155840.12 NP_000209.2 P51787-1Q96AI9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNQ1ENST00000155840.12 linkc.1034G>A p.Gly345Glu missense_variant, splice_region_variant Exon 8 of 16 1 NM_000218.3 ENSP00000155840.2 P51787-1

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152224
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.000478
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461606
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727096
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86250
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53324
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111862
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60376
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000131
AC:
2
AN:
152224
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.0000654
AC:
1
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
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:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68028
Other (OTH)
AF:
0.000478
AC:
1
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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:
0.0000279
Hom.:
0

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:4Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Long QT syndrome 1 Pathogenic:1
Jan 01, 1996
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not provided Pathogenic:1
Sep 17, 2024
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); Published functional studies demonstrate a damaging effect through dominant-negative suppression of potassium channel current (PMID: 10376919); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 31589614, 10376919, 15840476, 8528244) -

Long QT syndrome Pathogenic:1
Jan 07, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 345 of the KCNQ1 protein (p.Gly345Glu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with long QT syndrome (PMID: 8528244). It has also been observed to segregate with disease in related individuals. This variant is also known as G216E. ClinVar contains an entry for this variant (Variation ID: 3122). 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 disruptive. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 10376919). For these reasons, this variant has been classified as Pathogenic. -

Cardiac arrhythmia Pathogenic:1
May 16, 2024
Color Diagnostics, LLC DBA Color Health
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces glycine with glutamic acid at codon 345 of the KCNQ1 protein. This variant is found within the highly conserved transmembrane domain S6 (a.a. 328-348). Rare non-truncating variants in this region have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). Functional studies have shown that this variant causes a reduction of potassium channel current when expressed in xenopus oocytes (PMID: 10376919) and results in prolonged action potential duration in edited cardiomyocytes derived from induced human pluripotent stem cells (PMID: 25082577). This variant has been reported to segregate with long QT syndrome in at least 11 related carriers from a family (PMID: 8528244, 10376919). This variant has also been reported in another individual suspected of having long QT syndrome (PMID: 15840476). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). A different missense variant occurring at the same codon, p.Gly345Arg, is known to be disease-causing (Clinvar variation ID 200837), indicating that glycine at this position is a clinically important residue. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Congenital long QT syndrome Other:1
-
Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:8528244;PMID:10376919;PMID:15840476). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
CardioboostArm
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.59
D
BayesDel_noAF
Pathogenic
0.61
CADD
Pathogenic
34
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;.
Eigen
Pathogenic
0.80
Eigen_PC
Pathogenic
0.69
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
0.98
D;D
M_CAP
Pathogenic
0.98
D
MetaRNN
Pathogenic
0.99
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.8
H;.
PhyloP100
9.3
PrimateAI
Pathogenic
0.93
D
PROVEAN
Pathogenic
-7.5
D;D
REVEL
Pathogenic
0.97
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;D
Vest4
0.95
MutPred
0.91
Loss of catalytic residue at A344 (P = 0.0504);.;
MVP
0.99
MPC
1.3
ClinPred
1.0
D
GERP RS
3.8
Varity_R
0.99
gMVP
1.0
Mutation Taster
=3/97
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.65
dbscSNV1_RF
Benign
0.65
SpliceAI score (max)
0.19
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: rs120074183; hg19: chr11-2606443; API