rs74315446

Positions:

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_000219.6(KCNE1):c.221C>T(p.Ser74Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000756 in 1,455,162 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S74A) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000014 ( 0 hom., cov: 17)

Exomes 𝑓: 0.0000076 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

KCNE1
NM_000219.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:4O:1

Conservation

PhyloP100: 8.49

Variant links:

Genes affected

KCNE1 (HGNC:6240): (potassium voltage-gated channel subfamily E regulatory subunit 1) The product of this gene belongs to the potassium channel KCNE family. Potassium ion channels are essential to many cellular functions and show a high degree of diversity, varying in their electrophysiologic and pharmacologic properties. This gene encodes a transmembrane protein known to associate with the product of the KVLQT1 gene to form the delayed rectifier potassium channel. Mutation in this gene are associated with both Jervell and Lange-Nielsen and Romano-Ward forms of long-QT syndrome. Alternatively spliced transcript variants encoding the same protein have been identified. [provided by RefSeq, Jul 2008]

KCNE1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.86

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNE1	NM_000219.6 linkuse as main transcript	c.221C>T	p.Ser74Leu	missense_variant	4/4	ENST00000399286.3	NP_000210.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNE1	ENST00000399286.3 linkuse as main transcript	c.221C>T	p.Ser74Leu	missense_variant	4/4	1	NM_000219.6	ENSP00000382226	P1

Frequencies

GnomAD3 genomes

AF:

0.00

AC:

AN:

140560

Hom.:

Cov.:

FAILED QC

Gnomad AFR

AF:

0.0000263

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:

0.0000156

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251392

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135892

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.0000327

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000756

AC:

AN:

1455162

Hom.:

Cov.:

AF XY:

0.00000828

AC XY:

AN XY:

724338

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000814

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Data not reliable, filtered out with message: AS_VQSR

AF:

0.0000142

AC:

AN:

140672

Hom.:

Cov.:

AF XY:

0.0000294

AC XY:

AN XY:

68142

show subpopulations

Gnomad4 AFR

AF:

0.0000262

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:

0.0000156

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2Uncertain:4Other:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Long QT syndrome 5

Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Nov 01, 1997

- -

Long QT syndrome

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 28, 2023

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 74 of the KCNE1 protein (p.Ser74Leu). This variant is present in population databases (rs74315446, gnomAD 0.005%). This missense change has been observed in individuals with long QT syndrome (PMID: 9354802, 31941373; Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 13478). 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 expected to disrupt KCNE1 protein function with a positive predictive value of 80%. Experimental studies are conflicting or provide insufficient evidence to determine the effect of this variant on KCNE1 function (PMID: 9354802, 9834138, 19008479, 19907016, 32058015). For these reasons, this variant has been classified as Pathogenic. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 29, 2016

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Ser74Leu variant in KCNE1 has been previously reported in one individual with long-QT syn drome and reportedly segregated in two family members with elevated QTc interval s who did not display overt symptoms (Splawski 1997, Westenskow 2004). This vari ant has been identified in 2/66630 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs74315446). Computatio nal prediction tools and conservation analysis suggest that this variant may imp act the protein. In addition, in vitro functional studies provide some evidence that the p.Ser74Leu variant may have a mild effect on the normal function of the protein (Harmer 2010, McCrossan 2009, Sesti 1998). However, these types of assa ys may not accurately represent biological function. In summary, while there is some suspicion for a pathogenic role based on the reported family and in vitro s tudies, the clinical significance of this variant is uncertain. -

Long QT syndrome 5;C2676723:Jervell and Lange-Nielsen syndrome 2

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Nov 01, 2021

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jul 25, 2023

Functional studies have not been consistent in showing p.(S74L) has a damaging effect on channel function (Splawski et al., 1997; Garmany et al., 2020; Strutz-Seebohm et al., 2006; Chen et al., 2020); This variant is associated with the following publications: (PMID: 19907016, 9834138, 10973849, 16914890, 36921038, 30461122, 30930557, 37162834, 29661707, 32058015, 31834838, 19008479, 9354802, 31941373, 31521807, 24710009) -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 15, 2018

The c.221C>T (p.S74L) alteration is located in exon 3 (coding exon 1) of the KCNE1 gene. This alteration results from a C to T substitution at nucleotide position 221, causing the serine (S) at amino acid position 74 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Congenital long QT syndrome

Other:1

not provided, no classification provided

literature only

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:9354802;PMID:15051636;PMID:19907016). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.59

BayesDel_addAF

Pathogenic

0.31

BayesDel_noAF

Pathogenic

0.46

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.94

D;D;D;D;D;D;D;D

Eigen

Pathogenic

0.75

Eigen_PC

Uncertain

0.66

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.89

.;.;D;.;.;.;.;.

M_CAP

Uncertain

0.27

MetaRNN

Pathogenic

0.86

D;D;D;D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Uncertain

2.8

M;M;M;M;M;M;M;M

MutationTaster

Benign

1.0

A;A;A;A;A;A;A;A;A;A;A;A

PrimateAI

Uncertain

0.66

PROVEAN

Uncertain

-4.1

D;.;.;D;D;D;D;D

REVEL

Pathogenic

0.91

Sift

Uncertain

0.0030

D;.;.;D;D;D;D;D

Sift4G

Uncertain

0.0080

D;D;D;D;D;D;D;D

Polyphen

1.0

D;D;D;D;D;D;D;D

Vest4

0.60

MVP

0.98

MPC

0.41

ClinPred

0.97

GERP RS

5.2

Varity_R

0.51

gMVP

0.63

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

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