rs199472758

Positions:

• chr11-2583526-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PP3_Strong PP5_Moderate

The NM_000218.3(KCNQ1):​c.1013C>T​(p.Ser338Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.42

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 Pathogenic. Variant got 10 ACMG points.

• PM1: In a helix (size 19) in uniprot entity KCNQ1_HUMAN there are 35 pathogenic changes around while only 0 benign (100%) in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.977
• PP5: Variant 11-2583526-C-T is Pathogenic according to our data. Variant chr11-2583526-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 52928.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr11-2583526-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.1013C>T	p.Ser338Phe	missense_variant	7/16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.1013C>T	p.Ser338Phe	missense_variant	7/16	1	NM_000218.3	ENSP00000155840	P1
KCNQ1	ENST00000335475.6	c.632C>T	p.Ser211Phe	missense_variant	7/16	1		ENSP00000334497
KCNQ1	ENST00000496887.7	c.752C>T	p.Ser251Phe	missense_variant	8/16	5		ENSP00000434560
KCNQ1	ENST00000646564.2	c.569C>T	p.Ser190Phe	missense_variant	3/11			ENSP00000495806

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 08, 2022

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 23291057, 29167462). 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: 52928). This missense change has been observed in individuals with clinical features of long QT syndrome (PMID: 19862833, 23291057; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 338 of the KCNQ1 protein (p.Ser338Phe). -

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:19862833). 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	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	D;.;.
Eigen	Uncertain	0.63
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.0	M;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-5.7	D;.;D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D;.;D
Sift4G	Uncertain	0.0020	D;.;D
Polyphen		1.0	D;.;D
Vest4		0.96
MutPred		0.86		Loss of catalytic residue at S338 (P = 0.0231);.;.;
MVP		0.97
MPC		1.2
ClinPred		1.0	D
GERP RS		3.9
Varity_R		0.97
gMVP		0.96

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: rs199472758; hg19: chr11-2604756; COSMIC: COSV99326388;