rs199472777

Positions:

• chr11-2587634-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 0P and 0B.

The ENST00000155840.12(KCNQ1):​c.1193A>G​(p.Lys398Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000178 in 1,461,650 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: KCNQ1 ENST00000155840.12 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5 O:1
• Conservation: PhyloP100: 1.28

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 Uncertain_significance. Variant got 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.1193A>G	p.Lys398Arg	missense_variant	9/16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.1193A>G	p.Lys398Arg	missense_variant	9/16	1	NM_000218.3	ENSP00000155840	P1
KCNQ1	ENST00000335475.6	c.812A>G	p.Lys271Arg	missense_variant	9/16	1		ENSP00000334497
KCNQ1	ENST00000496887.7	c.836A>G	p.Lys279Arg	missense_variant	9/16	5		ENSP00000434560
KCNQ1	ENST00000646564.2	c.653A>G	p.Lys218Arg	missense_variant	4/11			ENSP00000495806

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000178 AC: 26 AN: 1461650 Hom.: 0 Cov.: 32 AF XY: 0.0000248 AC XY: 18 AN XY: 727128

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: 0.0000234

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000987 Hom.: 0

Bravo AF: 0.0000227

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Dec 01, 2023	This missense variant replaces lysine with arginine at codon 398 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual suspected to be affected with long QT syndrome (PMID: 19716085), in an individual affected with short QT syndrome (PMID: 36806574), in an individual affected with idiopathic ventricular fibrillation (PMID: 31114860), and in an individual affected with left bundle branch block as well as an unaffected carrier (PMID: 34930020). This variant has not been identified 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 13, 2023	This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 398 of the KCNQ1 protein (p.Lys398Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of long QT syndrome (PMID: 19716085). ClinVar contains an entry for this variant (Variation ID: 67021). Advanced 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 at Invitae 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. -

Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Sep 17, 2021

- -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 09, 2019

The c.1193A>G (p.K398R) alteration is located in exon 9 (coding exon 9) of the KCNQ1 gene. This alteration results from a A to G substitution at nucleotide position 1193, causing the lysine (K) at amino acid position 398 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Cardiac arrhythmia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

May 01, 2023

This missense variant replaces lysine with arginine at codon 398 of the KCNQ1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual suspected to be affected with long QT syndrome (PMID: 19716085), in an individual affected with short QT syndrome (PMID: 36806574), in an individual affected with idiopathic ventricular fibrillation (PMID: 31114860), and in an individual affected with left bundle branch block as well as an unaffected carrier (PMID: 34930020). This variant has not been identified 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

not provided, no classification provided

literature only

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

-

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	Benign	0.084
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Benign	18
DANN	Benign	0.89
DEOGEN2	Benign	0.35	T;.;.
Eigen	Benign	-0.64
Eigen_PC	Benign	-0.52
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Benign	0.80	T;T;T
M_CAP	Uncertain	0.20	D
MetaRNN	Uncertain	0.43	T;T;T
MetaSVM	Uncertain	0.52	D
MutationAssessor	Benign	0.90	L;.;.
MutationTaster	Benign	0.97	D;D
PrimateAI	Uncertain	0.50	T
PROVEAN	Benign	-0.65	N;.;N
REVEL	Pathogenic	0.65
Sift	Benign	0.50	T;.;T
Sift4G	Benign	0.58	T;.;T
Polyphen		0.0040	B;.;B
Vest4		0.25
MVP		0.90
MPC		0.31
ClinPred		0.14	T
GERP RS		2.5
Varity_R		0.054
gMVP		0.62

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: rs199472777; hg19: chr11-2608864;