rs199472796

Variant names:

• chr11-2775990-G-A
• rs199472796
• NM_000218.3:c.1621G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PP3_Strong

The NM_000218.3(KCNQ1):​c.1621G>A​(p.Val541Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000338 in 1,570,346 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 Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000035 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:1 U:9 O:1
• Conservation: PhyloP100: 7.54

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a region_of_interest Interaction with KCNE1 C-terminus (size 37) in uniprot entity KCNQ1_HUMAN there are 36 pathogenic changes around while only 1 benign (97%) in NM_000218.3
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.956

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.1621G>A	p.Val541Ile	missense_variant	Exon 13 of 16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.1621G>A	p.Val541Ile	missense_variant	Exon 13 of 16	1	NM_000218.3	ENSP00000155840.2
KCNQ1	ENST00000335475.6	c.1240G>A	p.Val414Ile	missense_variant	Exon 13 of 16	1		ENSP00000334497.5
KCNQ1	ENST00000496887.7	c.1264G>A	p.Val422Ile	missense_variant	Exon 13 of 16	5		ENSP00000434560.2
KCNQ1	ENST00000646564.2	c.1081G>A	p.Val361Ile	missense_variant	Exon 8 of 11			ENSP00000495806.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152188 Hom.: 0 Cov.: 33

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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000271 AC: 5 AN: 184336 Hom.: 0 AF XY: 0.0000102 AC XY: 1 AN XY: 97640

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000758

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: 0.0000383

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000353 AC: 50 AN: 1418158 Hom.: 0 Cov.: 31 AF XY: 0.0000399 AC XY: 28 AN XY: 700936

Gnomad4 AFR exome AF: 0.0000304

Gnomad4 AMR exome AF: 0.0000537

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000265

Gnomad4 SAS exome AF: 0.0000373

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000358

Gnomad4 OTH exome AF: 0.0000509

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152188 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74358

Gnomad4 AFR AF: 0.0000241

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: 0.0000294

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000474 Hom.: 0

Bravo AF: 0.0000378

ExAC AF: 0.0000254 AC: 3

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:9 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:3

Jan 06, 2022

AiLife Diagnostics, AiLife Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 30, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported in at least one individual in association with LQTS (Kapplinger et al., 2009; Kapplinger et al., 2015); Reported in ClinVar as a variant of uncertain significance by several other clinical laboratories (ClinVar Variant ID#67043; Landrum et al., 2016); Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 19716085, 25854863, 22581653, 29021305, 32048431, 32233023) -

Sep 09, 2021

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Long QT syndrome Uncertain:2

Oct 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 541 of the KCNQ1 protein (p.Val541Ile). 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 missense change has been observed in individual(s) with clinical features of long QT syndrome (LQTS) (PMID: 19716085; internal data). ClinVar contains an entry for this variant (Variation ID: 67043). 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. 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. -

Dec 13, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces valine with isoleucine at codon 541 of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic testing (PMID: 19716085). This variant has been identified in 5/184336 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Long QT syndrome 1 Pathogenic:1

Jul 22, 2019

Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues

Significance: Likely pathogenic

Review Status: flagged submission

Collection Method: clinical testing

- -

not specified Uncertain:1

Jul 26, 2016

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: Reported in 1 LQT proband; ClinVar: Path by GeneDx -

Wolff-Parkinson-White pattern Uncertain:1

Jul 14, 2017

Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: research

This variant was identified in an individual with Wolff-Parkinson-White syndrome -

Cardiovascular phenotype Uncertain:1

Mar 22, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1621G>A (p.V541I) alteration is located in exon 13 (coding exon 13) of the KCNQ1 gene. This alteration results from a G to A substitution at nucleotide position 1621, causing the valine (V) at amino acid position 541 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia Uncertain:1

Jul 07, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces valine with isoleucine at codon 541 of the KCNQ1 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic testing (PMID: 19716085). This variant has been identified in 5/184336 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

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:19716085). 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	0.81
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;.;.
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Pathogenic	0.96	D
MutationAssessor	Pathogenic	3.1	M;.;.
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-0.87	N;.;N
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0010	D;.;D
Sift4G	Pathogenic	0.0	D;.;D
Polyphen		0.99	D;.;D
Vest4		0.76
MutPred		0.83		Loss of phosphorylation at Y545 (P = 0.0939);.;.;
MVP		0.98
MPC		1.0
ClinPred		0.90	D
GERP RS		3.8
Varity_R		0.77
gMVP		0.99

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

Other links and lift over

dbSNP: rs199472796; hg19: chr11-2797220;