11-2588804-C-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.

This summary comes from the ClinGen Evidence Repository: NM_000218.3(KCNQ1):c.1343C>A is a missense variant predicted to cause substitution of proline by glutamine at amino acid 448 (p.Pro448Gln). To our knowledge, this variant has not been reported in the literature in any individuals with long QT syndrome 1. This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.0001538, with 14 alleles / 91008 total alleles in the South Asian population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004, so neither criterion is met. To our knowledge, functional assays have not been reported for this variant. The computational predictor REVEL gives a score of 0.512, which is below the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.75 but higher than the BP4 threshold of <0.25 and does not strongly predict a damaging effect on KCNQ1 function. The computational splicing predictor SpliceAI gives a score of 0.00 for donor and acceptor gain and loss, which is lower than the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of greater than or equal to 0.2 and does not strongly predict a damaging effect on KCNQ1 splicing. In summary, this variant meets the criteria to be classified as a variant of uncertain significance due to insufficient evidence for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP. (VCEP specifications version 1.0.0; date of approval 03/04/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA028774/MONDO:0100316/112

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

1
4
14

Clinical Significance

Uncertain significance reviewed by expert panel U:3B:2

Conservation

PhyloP100: -0.179

Publications

48 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: G2P, Labcorp Genetics (formerly Invitae)
  • 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: Uncertain_significance. The variant received 0 ACMG points.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ1
NM_000218.3
MANE Select
c.1343C>Ap.Pro448Gln
missense
Exon 10 of 16NP_000209.2
KCNQ1
NM_001406836.1
c.1247C>Ap.Pro416Gln
missense
Exon 9 of 15NP_001393765.1
KCNQ1
NM_001406837.1
c.1073C>Ap.Pro358Gln
missense
Exon 11 of 17NP_001393766.1

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
KCNQ1
ENST00000155840.12
TSL:1 MANE Select
c.1343C>Ap.Pro448Gln
missense
Exon 10 of 16ENSP00000155840.2P51787-1
KCNQ1
ENST00000335475.6
TSL:1
c.962C>Ap.Pro321Gln
missense
Exon 10 of 16ENSP00000334497.5P51787-2
KCNQ1
ENST00000910997.1
c.1340C>Ap.Pro447Gln
missense
Exon 10 of 16ENSP00000581056.1

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152086
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000719
AC:
18
AN:
250376
AF XY:
0.0000590
show subpopulations
Gnomad AFR exome
AF:
0.0000619
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000151
AC:
22
AN:
1461180
Hom.:
0
Cov.:
32
AF XY:
0.0000151
AC XY:
11
AN XY:
726868
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33472
American (AMR)
AF:
0.0000224
AC:
1
AN:
44704
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.000151
AC:
13
AN:
86190
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53132
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5566
European-Non Finnish (NFE)
AF:
0.00000360
AC:
4
AN:
1111936
Other (OTH)
AF:
0.0000663
AC:
4
AN:
60358
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.473
Heterozygous variant carriers
0
1
3
4
6
7
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:
152204
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
74414
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41548
American (AMR)
AF:
0.00
AC:
0
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5146
South Asian (SAS)
AF:
0.000208
AC:
1
AN:
4818
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
67998
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
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
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000988
AC:
12
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:reviewed by expert panel
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
1
1
Long QT syndrome (2)
-
1
-
Cardiac arrhythmia (1)
-
-
1
Cardiovascular phenotype (1)
-
1
-
Long QT syndrome 1 (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.077
CardioboostArm
Benign
0.0018
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Uncertain
-0.060
CADD
Benign
1.3
DANN
Benign
0.89
DEOGEN2
Uncertain
0.54
D
Eigen
Benign
-0.83
Eigen_PC
Benign
-0.80
FATHMM_MKL
Benign
0.10
N
LIST_S2
Benign
0.47
T
M_CAP
Pathogenic
0.38
D
MetaRNN
Benign
0.096
T
MetaSVM
Uncertain
0.69
D
MutationAssessor
Benign
0.69
N
PhyloP100
-0.18
PrimateAI
Benign
0.24
T
PROVEAN
Benign
-0.77
N
REVEL
Uncertain
0.51
Sift
Benign
0.12
T
Sift4G
Benign
0.61
T
Polyphen
0.0010
B
Vest4
0.25
MutPred
0.27
Loss of catalytic residue at P447 (P = 0.0102)
MVP
0.93
MPC
0.34
ClinPred
0.030
T
GERP RS
4.1
Varity_R
0.043
gMVP
0.32
Mutation Taster
=69/31
polymorphism

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

Other links and lift over

dbSNP: rs12720449; hg19: chr11-2610034; API