rs199473445

Variant names:

• chr11-2445268-G-A
• rs199473445
• NM_000218.3:c.170G>A

Your query was ambiguous. Multiple possible variants found:

• chr11-2445268-G-A
• chr11-2445268-G-T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_000218.3(KCNQ1):​c.170G>A​(p.Gly57Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000927 in 1,078,828 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G57V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 9.3e-7 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.662
• Publications: 0 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: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3312837).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.170G>A	p.Gly57Asp	missense_variant	Exon 1 of 16	ENST00000155840.12	NP_000209.2
KCNQ1	NM_001406836.1	c.170G>A	p.Gly57Asp	missense_variant	Exon 1 of 15		NP_001393765.1
KCNQ1	NM_001406838.1	c.170G>A	p.Gly57Asp	missense_variant	Exon 1 of 11		NP_001393767.1
KCNQ1	NM_001406837.1	c.-193G>A		5_prime_UTR_variant	Exon 1 of 17		NP_001393766.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.170G>A	p.Gly57Asp	missense_variant	Exon 1 of 16	1	NM_000218.3	ENSP00000155840.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 9.27e-7 AC: 1 AN: 1078828 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 517016

African (AFR) AF: 0.00 AC: 0 AN: 21114

American (AMR) AF: 0.00 AC: 0 AN: 7642

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 12960

East Asian (EAS) AF: 0.00 AC: 0 AN: 23986

South Asian (SAS) AF: 0.00 AC: 0 AN: 23482

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 20916

Middle Eastern (MID) AF: 0.000353 AC: 1 AN: 2834

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 923608

Other (OTH) AF: 0.00 AC: 0 AN: 42286

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

May 09, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

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 57 of the KCNQ1 protein (p.Gly57Asp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with KCNQ1-related conditions. ClinVar contains an entry for this variant (Variation ID: 1057004). 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 not expected to disrupt 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
CardioboostArm	Uncertain	0.11
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	17
DANN	Uncertain	0.98
DEOGEN2	Benign	0.27	T
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.54
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.32	T
M_CAP	Pathogenic	0.99	D
MetaRNN	Benign	0.33	T
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Benign	1.5	L
PhyloP100		0.66
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	0.45	N
REVEL	Uncertain	0.34
Sift	Benign	0.48	T
Sift4G	Benign	0.20	T
Polyphen		0.81	P
Vest4		0.17
MutPred		0.24		Loss of catalytic residue at P53 (P = 0.0681);
MVP		0.92
MPC		1.5
ClinPred		0.48	T
GERP RS		2.4
PromoterAI		-0.072	Neutral
Varity_R		0.066
gMVP		0.24
Mutation Taster		=74/26	polymorphism

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: rs199473445; hg19: chr11-2466498;