NM_000218.3:c.535G>C

Variant names:

• chr11-2570685-G-C
• NM_000218.3:c.535G>C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP3_Strong PP5_Moderate

The NM_000218.3(KCNQ1):​c.535G>C​(p.Gly179Arg) 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G179S) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.38

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.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr11-2570685-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 11-2570685-G-C is Pathogenic according to our data. Variant chr11-2570685-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2446426.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.535G>C	p.Gly179Arg	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.535G>C	p.Gly179Arg	missense_variant	Exon 3 of 16	1	NM_000218.3	ENSP00000155840.2
KCNQ1	ENST00000335475.6	c.154G>C	p.Gly52Arg	missense_variant	Exon 3 of 16	1		ENSP00000334497.5
KCNQ1	ENST00000496887.7	c.274G>C	p.Gly92Arg	missense_variant	Exon 4 of 16	5		ENSP00000434560.2
KCNQ1	ENST00000646564.2	c.478-12750G>C		intron_variant	Intron 2 of 10			ENSP00000495806.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome 1 Pathogenic:1

Sep 30, 2022

Petrovsky National Research Centre of Surgery, The Federal Agency for Scientific Organizations

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

We observed a c.535G>C (p.Gly179Arg) genetic variant in the KCNQ1 gene on WES data in a 6-y.o. male proband, diagnosed with borderline QTc prolongation up to 465 ms. This variant is not present in gnomAD database and located in a mutational hot spot and/or critical and well-established functional domain (PM1_strong according to Walsh R. et al. (PMID: 32893267)). Multiple computational resources predict deleterious effect of p.Gly179Arg genetic variant. We assume that the c.535G>C (p.Gly179Arg) variant could be classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	.;D;.
Eigen	Uncertain	0.59
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.89	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	1.6	.;L;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-7.5	D;D;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	.;D;.
Vest4		0.93, 0.93
MutPred		0.93		.;Gain of MoRF binding (P = 0.0412);.;
MVP		0.98
MPC		1.3
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.93
gMVP		0.98

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-2591915;