11-2572979-G-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):ā€‹c.914G>Cā€‹(p.Trp305Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,482 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 Pathogenic (ā˜…ā˜…). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W305L) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes š‘“: 6.8e-7 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

16
2
1

Clinical Significance

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

Conservation

PhyloP100: 9.36
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PM1
In a intramembrane_region Pore-forming; Name=Segment H5 (size 20) in uniprot entity KCNQ1_HUMAN there are 54 pathogenic changes around while only 0 benign (100%) 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 chr11-2572979-G-T is described in Lovd as [Pathogenic].
PP3
MetaRNN computational evidence supports a deleterious effect, 0.995
PP5
Variant 11-2572979-G-C is Pathogenic according to our data. Variant chr11-2572979-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 3127.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2572979-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNQ1NM_000218.3 linkc.914G>C p.Trp305Ser missense_variant Exon 6 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.914G>C p.Trp305Ser missense_variant Exon 6 of 16 1 NM_000218.3 ENSP00000155840.2 P51787-1
KCNQ1ENST00000335475.6 linkc.533G>C p.Trp178Ser missense_variant Exon 6 of 16 1 ENSP00000334497.5 P51787-2
KCNQ1ENST00000496887.7 linkc.653G>C p.Trp218Ser missense_variant Exon 7 of 16 5 ENSP00000434560.2 E9PPZ0
KCNQ1ENST00000646564.2 linkc.478-10456G>C intron_variant Intron 2 of 10 ENSP00000495806.2 A0A2R8YEQ9

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.00000401
AC:
1
AN:
249180
Hom.:
0
AF XY:
0.00000740
AC XY:
1
AN XY:
135116
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:
0.00000889
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460482
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
726452
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.00e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.00000824
AC:
1

ClinVar

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

Submissions by phenotype

Jervell and Lange-Nielsen syndrome 1 Pathogenic:1
Mar 01, 1998
OMIM
Significance: Pathogenic
Review Status: no assertion criteria provided
Collection Method: literature only

- -

not provided Pathogenic:1
Dec 13, 2023
GeneDx
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Identified in patients with LQTS and JLNS referred for genetic testing at GeneDx and in published literature (PMID: 9020846, 9781056, 15840476, 19490272, 19716085, 22456477, 23158531); Observed in homozygous state in a patient in published literature with JLNS and not observed in homozygous state in controls (PMID: 9781056, 9020846); Published functional studies demonstrate a damaging effect as the W305S variant results in decreased potassium channel current (PMID: 9312006); Not observed at a 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: 19716085, 26344792, 9781056, 34505893, 10973849, 17999538, 15840476, 19490272, 23158531, 21451124, 22456477, 26669661, 32383558, 34076677, 9020846, 9312006) -

Long QT syndrome Pathogenic:1
Apr 30, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Trp305 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been observed in individuals with KCNQ1-related conditions (PMID: 22949429, 26344792), which suggests that this may be a clinically significant amino acid residue. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 9312006, 10090886, 21451124, 26344792). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 3127). This missense change has been observed in individuals with clinical features of long QT syndrome and Jervell and Lange-Nielsen syndrome (PMID: 9781056, 15840476, 19490272, 19716085, 21451124, 22456477, 23139254). It has also been observed to segregate with disease in related individuals. This variant is present in population databases (rs120074186, gnomAD 0.0009%). This sequence change replaces tryptophan, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 305 of the KCNQ1 protein (p.Trp305Ser). -

Cardiovascular phenotype Pathogenic:1
Mar 31, 2022
Ambry Genetics
Significance: Pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.W305S variant (also known as c.914G>C), located in coding exon 6 of the KCNQ1 gene, results from a G to C substitution at nucleotide position 914. The tryptophan at codon 305 is replaced by serine, an amino acid with highly dissimilar properties, and is located in the pore region of the protein. This variant has been reported in individuals and families with long QT syndrome (LQTS), as well as in LQTS clinical genetic testing cohorts; however, individual clinical details were limited (Tester DJ et al. Heart Rhythm, 2005;2:507-17; Jons C et al. Sci Transl Med, 2011 Mar;3:76ra28; Itoh H et al. Eur J Hum Genet, 2016 08;24:1160-6). This alteration was also detected in three homozygous cases, including two siblings and an unrelated proband, with autosomal recessive Jervell and Lange-Nielsen syndrome (Neyroud N et al. Eur. J. Hum. Genet. 1998;6:129-33). In vitro functional analyses suggest that this variant significantly reduces potassium current, although in one study the impact was lessened when the alteration was co-expressed with wildtype KCNQ1 (Chouabe C et al. EMBO J. 1997;16:5472-9; Jons C et al. Sci Transl Med. 2011;3:76ra28). Internal structural analysis indicates that this alteration is moderately disruptive in a sensitive region and more disruptive than a nearby known pathogenic variant (Ambry internal data). In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

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:9781056;PMID:15840476;PMID:19716085;PMID:9312006;PMID:17999538). 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
0.99
BayesDel_addAF
Pathogenic
0.57
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
34
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.99
D;.
Eigen
Pathogenic
0.83
Eigen_PC
Pathogenic
0.71
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D;D
M_CAP
Pathogenic
0.96
D
MetaRNN
Pathogenic
1.0
D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.2
H;.
PrimateAI
Uncertain
0.73
T
PROVEAN
Pathogenic
-14
D;D
REVEL
Pathogenic
0.95
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;D
Vest4
1.0
MutPred
0.95
Gain of glycosylation at W305 (P = 0.0053);.;
MVP
1.0
MPC
1.5
ClinPred
1.0
D
GERP RS
3.9
Varity_R
1.0
gMVP
1.0

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
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: rs120074186; hg19: chr11-2594209; API