rs764455359

Positions:

• chr11-2445372-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000218.3(KCNQ1):​c.274T>C​(p.Ser92Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000277 in 1,445,538 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. S92C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000028 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.53

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ1	NM_000218.3	c.274T>C	p.Ser92Pro	missense_variant	1/16	ENST00000155840.12
KCNQ1	NM_001406836.1	c.274T>C	p.Ser92Pro	missense_variant	1/15
KCNQ1	NM_001406838.1	c.274T>C	p.Ser92Pro	missense_variant	1/11
KCNQ1	NM_001406837.1	c.-89T>C		5_prime_UTR_variant	1/17

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ1	ENST00000155840.12	c.274T>C	p.Ser92Pro	missense_variant	1/16	1	NM_000218.3	P1
KCNQ1	ENST00000345015.4	n.51T>C		non_coding_transcript_exon_variant	1/3	1
KCNQ1	ENST00000646564.2	c.274T>C	p.Ser92Pro	missense_variant	1/11
KCNQ1	ENST00000496887.7	c.24-11T>C		splice_polypyrimidine_tract_variant, intron_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000224 AC: 5 AN: 222730 Hom.: 0 AF XY: 0.00000807 AC XY: 1 AN XY: 123972

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000147

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000277 AC: 4 AN: 1445538 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 719602

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000895

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000845 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Long QT syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 14, 2018

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C15"). This sequence change replaces serine with proline at codon 92 of the KCNQ1 protein (p.Ser92Pro). The serine residue is highly conserved and there is a moderate physicochemical difference between serine and proline. This variant is present in population databases (rs764455359, ExAC 0.01%). This variant has not been reported in the literature in individuals with KCNQ1-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.51
BayesDel_addAF	Benign	-0.012	T
BayesDel_noAF	Uncertain	0.0
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.60	D
Eigen	Benign	-0.094
Eigen_PC	Benign	-0.15
FATHMM_MKL	Benign	0.73	D
LIST_S2	Benign	0.69	T
M_CAP	Pathogenic	0.97	D
MetaRNN	Uncertain	0.45	T
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	1.3	L
MutationTaster	Benign	0.56	N
PrimateAI	Pathogenic	0.92	D
PROVEAN	Benign	-1.8	N
REVEL	Uncertain	0.59
Sift	Uncertain	0.014	D
Sift4G	Benign	0.23	T
Polyphen		0.049	B
Vest4		0.20
MutPred		0.31		Loss of phosphorylation at S92 (P = 0.0264);
MVP		0.95
MPC		2.1
ClinPred		0.42	T
GERP RS		1.9
Varity_R		0.47
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs764455359; hg19: chr11-2466602;