rs397508070

Positions:

chr11-2583546-G-A

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_ModeratePM2PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):c.1032+1G>A variant causes a splice donor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,208 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KCNQ1
NM_000218.3 splice_donor

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 9.32

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.043171115 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.5, offset of 15, new splice context is: tggGTgcgt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 11-2583546-G-A is Pathogenic according to our data. Variant chr11-2583546-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 52937.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2583546-G-A is described in Lovd as [Pathogenic]. Variant chr11-2583546-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ1	NM_000218.3 linkuse as main transcript	c.1032+1G>A		splice_donor_variant		ENST00000155840.12

Ensembl

Gene	Transcript	HGVSc	Effect	TSL	MANE	Appris	UniProt
KCNQ1	ENST00000155840.12 linkuse as main transcript	c.1032+1G>A	splice_donor_variant	1	NM_000218.3	P1	P51787-1
KCNQ1	ENST00000335475.6 linkuse as main transcript	c.651+1G>A	splice_donor_variant	1			P51787-2
KCNQ1	ENST00000496887.7 linkuse as main transcript	c.771+1G>A	splice_donor_variant	5
KCNQ1	ENST00000646564.2 linkuse as main transcript	c.588+1G>A	splice_donor_variant

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AC0;AS_VQSR

AF:

0.00

AC:

AN:

1456396

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

724854

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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

AF:

0.00000657

AC:

AN:

152208

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74344

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Long QT syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 16, 2023	This sequence change affects a donor splice site in intron 7 of the KCNQ1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in KCNQ1 are known to be pathogenic (PMID: 9323054, 19862833). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individuals with long QT syndrome (PMID: 16244680, 19716085, 26132555, 34319147, 34505893). ClinVar contains an entry for this variant (Variation ID: 52937). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, no assertion criteria provided	research	Medical Research Institute, Tokyo Medical and Dental University	-	- -

not provided

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Nov 27, 2023

Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 16244680, 19716085, 18752142, 19862833, 34319147, 34505893, 26132555) -

Cardiovascular phenotype

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 29, 2022

The c.1032+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 7 of the KCNQ1 gene. This alteration has been reported in subjects with features of long QT syndrome (LQTS) and was shown to segregate with disease in one family (Kapplinger JD et al. Heart Rhythm, 2009 Sep;6:1297-303; Shigemizu D et al. PLoS One, 2015 Jul;10:e0130329; Choi SH et al. Circ Genom Precis Med, 2021 Aug;14:e003300). Another alteration impacting the same site (c.1032G>A (p.A344A)) has been shown to have a similar impact on splicing (Wuriyanghai Y et al. Heart Rhythm, 2018 Oct;15:1566-1574). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site and will result in the creation or strengthening of a novel splice donor site. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.24

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.87

FATHMM_MKL

Uncertain

0.93

MutationTaster

Benign

1.0

D;D

GERP RS

3.8

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

0.97

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.69

Position offset: 14

DS_DL_spliceai

0.97

Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over