rs199473399

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP2PP3_StrongPP5

The NM_000218.3(KCNQ1):​c.560T>C​(p.Leu187Pro) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,180 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L187R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

6
6
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2O:1

Conservation

PhyloP100: 5.84

Publications

7 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 12 ACMG points.

PM1
In a hotspot region, there are 17 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 23 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 chr11-2570710-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 843851.
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, 0.971
PP5
Variant 11-2570710-T-C is Pathogenic according to our data. Variant chr11-2570710-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 53066.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ1NM_000218.3 linkc.560T>C p.Leu187Pro missense_variant Exon 3 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.560T>C p.Leu187Pro missense_variant Exon 3 of 16 1 NM_000218.3 ENSP00000155840.2 P51787-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.00000801
AC:
2
AN:
249636
AF XY:
0.00000739
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000177
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460180
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726478
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26126
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51766
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111984
Other (OTH)
AF:
0.00
AC:
0
AN:
60380
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
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00000990
Hom.:
0
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:2Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Long QT syndrome 1 Pathogenic:1
Aug 01, 2023
Molecular Genetics Laboratory - Cardiogenetics, CHU de Nantes
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Long QT syndrome Pathogenic:1
Jan 30, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 187 of the KCNQ1 protein (p.Leu187Pro). This variant is present in population databases (rs199473399, gnomAD 0.002%). This missense change has been observed in individual(s) with long QT syndrome (PMID: 18808722, 23631430). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 53066). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KCNQ1 protein function. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on KCNQ1 function (PMID: 30571187, 32797034). For these reasons, this variant has been classified as Pathogenic. -

not provided Uncertain:1
Jul 25, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Identified in an individual suspected of having long QT syndrome, however specific clinical information was not provided (PMID: 23631430); Identified in several individuals with long QT syndrome in a large family, however the variant was also seen in several family members with an uncertain long QT syndrome diagnosis and in one unaffected family member making it unclear if the variant is segregating with disease in the family (PMID: 18808722); Not observed at significant frequency in large population cohorts (gnomAD); 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: 30571187, 23631430, 18808722) -

Cardiovascular phenotype Uncertain:1
Feb 12, 2018
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.560T>C (p.L187P) alteration is located in exon 3 (coding exon 3) of the KCNQ1 gene. This alteration results from a T to C substitution at nucleotide position 560, causing the leucine (L) at amino acid position 187 to be replaced by a proline (P). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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:18808722). 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
Benign
0.21
CardioboostArm
Uncertain
0.44
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.44
CADD
Uncertain
25
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.94
.;D;.
Eigen
Benign
0.027
Eigen_PC
Benign
0.13
FATHMM_MKL
Benign
0.60
D
LIST_S2
Uncertain
0.90
D;D;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.97
D;D;D
MetaSVM
Pathogenic
0.88
D
MutationAssessor
Benign
1.9
.;L;.
PhyloP100
5.8
PrimateAI
Uncertain
0.59
T
PROVEAN
Uncertain
-4.2
D;D;D
REVEL
Pathogenic
0.77
Sift
Benign
0.18
T;D;D
Sift4G
Benign
0.33
T;T;T
Polyphen
0.047
.;B;.
Vest4
0.90, 0.81
MutPred
0.92
.;Loss of stability (P = 0.0531);.;
MVP
0.96
MPC
0.63
ClinPred
0.82
D
GERP RS
4.4
Varity_R
0.88
gMVP
0.97
Mutation Taster
=12/88
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
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: rs199473399; hg19: chr11-2591940; API