NM_000218.3:c.557G>A

Variant names:

• chr11-2570707-G-A
• rs794728568
• NM_000218.3:c.557G>A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.557G>A​(p.Gly186Asp) 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. 13/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G186R) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.59
• Publications: 6 publications found

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: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P
• 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

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 20 uncertain 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 chr11-2570706-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 53065.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome type 2, long QT syndrome 1, Jervell and Lange-Nielsen syndrome 1, long QT syndrome, short QT syndrome, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy, familial atrial fibrillation, atrial fibrillation, familial, 3.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 11-2570707-G-A is Pathogenic according to our data. Variant chr11-2570707-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 207967.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.557G>A	p.Gly186Asp	missense_variant	Exon 3 of 16	ENST00000155840.12	NP_000209.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.557G>A	p.Gly186Asp	missense_variant	Exon 3 of 16	1	NM_000218.3	ENSP00000155840.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome 1 Pathogenic:1

Jan 01, 2013

Institute of Medical Genetics and Genomics, Sir Ganga Ram Hospital

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

not provided Pathogenic:1

Sep 10, 2020

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital long QT syndrome Pathogenic:1

May 04, 2018

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Gly186Asp variant in KCNQ1 has been reported in the heterozygous state in 2 individuals with long QT syndrome (LQTS) and in the homozygous state in 1 indi vidual with Jervell and Lange-Nielsen syndrome (Vyas 2016a, Vyas 2016b, Itoh 201 6). Additionally, the variant segregated with prolonged QT interval in 5 individ uals from 2 families (Vyas 2016a, Vyas 2016b), and was absent from large populat ion studies. Computational prediction tools and conservation analysis suggest th at the variant may impact the protein, though this information is not predictive enough to determine pathogenicity. Finally, several variants at the same positi on have been reported in individuals with LQTS (ClinVar variation IDs: 432149, 2 00894, 53065, 67082); however, their clinical significance is unknown due to lim ited available data. In summary, although additional studies are required to ful ly establish its clinical significance, the p.Gly186Asp variant is likely pathog enic. ACMG/AMP Criteria applied: PM2, PP1_Moderate, PP3, PS4_Supporting. -

Long QT syndrome Pathogenic:1

Aug 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 186 of the KCNQ1 protein (p.Gly186Asp). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with Jervell and Lange-Nielsen syndrome and long QT syndrome (PMID: 26669661, 27041150, 27485560, 34930020). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 207967). 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) performed at Invitae indicates that this missense variant is expected to disrupt KCNQ1 protein function with a positive predictive value of 95%. This variant disrupts the p.Gly186 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been observed in individuals with KCNQ1-related conditions (PMID: 22949429, 27041150, 27485560), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. -

Cardiac arrhythmia Pathogenic:1

Apr 08, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces glycine with aspartic acid at codon 186 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 individuals affected with long QT syndrome in the heterozygous state and in an individual with Jervell and Lange-Nielsen syndrome in the homozygous state (PMID: 26669661, 27041150). This variant has been shown to segregate with long QT syndrome in two families (PMID: 27041150, 27485560). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	.;D;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	.;M;.
PhyloP100		7.6
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-6.6	D;D;D
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	D;D;D
Sift4G	Uncertain	0.046	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.92, 0.74
MutPred		0.87		.;Loss of catalytic residue at G186 (P = 0.0219);.;
MVP		0.98
MPC		1.3
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.89
gMVP		0.99
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs794728568; hg19: chr11-2591937;