NM_000218.3:c.1885G>C

Variant names:

• chr11-2847857-G-C
• rs775608046
• NM_000218.3:c.1885G>C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_000218.3(KCNQ1):​c.1885G>C​(p.Gly629Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000141 in 1,422,110 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/23 in silico tools predict 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. G629S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0150
• 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-AS1 (HGNC:42790): (KCNQ1 antisense RNA 1)

ACMG classification

Our verdict: Uncertain_significance. The variant received 1 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=0.14105338).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	NM_000218.3	MANE Select	c.1885G>C	p.Gly629Arg	missense	Exon 16 of 16	NP_000209.2
	KCNQ1	NM_001406836.1		c.1789G>C	p.Gly597Arg	missense	Exon 15 of 15	NP_001393765.1
	KCNQ1	NM_001406837.1		c.1615G>C	p.Gly539Arg	missense	Exon 17 of 17	NP_001393766.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.1885G>C	p.Gly629Arg	missense	Exon 16 of 16	ENSP00000155840.2
	KCNQ1	ENST00000335475.6	TSL:1	c.1504G>C	p.Gly502Arg	missense	Exon 16 of 16	ENSP00000334497.5
	KCNQ1	ENST00000713725.1		c.1744G>C	p.Gly582Arg	missense	Exon 15 of 15	ENSP00000519029.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000141 AC: 2 AN: 1422110 Hom.: 0 Cov.: 31 AF XY: 0.00000142 AC XY: 1 AN XY: 703746

African (AFR) AF: 0.00 AC: 0 AN: 32644

American (AMR) AF: 0.00 AC: 0 AN: 39808

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25410

East Asian (EAS) AF: 0.00 AC: 0 AN: 37478

South Asian (SAS) AF: 0.00 AC: 0 AN: 81182

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49216

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5716

European-Non Finnish (NFE) AF: 0.00000183 AC: 2 AN: 1091850

Other (OTH) AF: 0.00 AC: 0 AN: 58806

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jan 10, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.098
CardioboostArm	Benign	0.0018
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	0.90
DANN	Benign	0.46
DEOGEN2	Benign	0.34	T
Eigen	Benign	-1.5
Eigen_PC	Benign	-1.5
FATHMM_MKL	Benign	0.017	N
LIST_S2	Benign	0.45	T
M_CAP	Pathogenic	0.37	D
MetaRNN	Benign	0.14	T
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Benign	0.76	N
PhyloP100		-0.015
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-0.35	N
REVEL	Uncertain	0.60
Sift	Benign	0.17	T
Sift4G	Benign	0.28	T
Polyphen		0.0020	B
Vest4		0.071
MutPred		0.42		Gain of methylation at G629 (P = 0.0645)
MVP		0.71
MPC		0.44
ClinPred		0.041	T
GERP RS		-1.1
Varity_R		0.049
gMVP		0.39
Mutation Taster		=37/63	disease causing

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: rs775608046; hg19: chr11-2869087;