rs281865421

Variant names:

• chr21-34449458-CAGGGT-AGGGGG
• rs281865421
• NM_000219.6:c.172_177delACCCTGinsCCCCCT

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PP5_Very_Strong

The NM_000219.6(KCNE1):​c.172_177delACCCTGinsCCCCCT​(p.ThrLeu58ProPro) variant causes a missense change. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. T58T) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 17)
• Consequence: KCNE1 NM_000219.6 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 6.68
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• long QT syndrome 5

  Inheritance: AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: ClinGen, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• Jervell and Lange-Nielsen syndrome 2

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, PanelApp Australia
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• atrial fibrillation

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PP5: Variant 21-34449458-CAGGGT-AGGGGG is Pathogenic according to our data. Variant chr21-34449458-CAGGGT-AGGGGG is described in ClinVar as [Likely_pathogenic]. Clinvar id is 13475.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNE1	NM_000219.6	c.172_177delACCCTGinsCCCCCT	p.ThrLeu58ProPro	missense_variant		ENST00000399286.3	NP_000210.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNE1	ENST00000399286.3	c.172_177delACCCTGinsCCCCCT	p.ThrLeu58ProPro	missense_variant		1	NM_000219.6	ENSP00000382226.2

Frequencies

GnomAD3 genomes Cov.: 17

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 17

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Long QT syndrome 5;C2676723:Jervell and Lange-Nielsen syndrome 2 Pathogenic:1

Oct 21, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Jun 06, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (gnomAD); Published functional studies demonstrate that the p.(T58P)/p.(L59P) variant severely weakens the interaction of KCNE1 with KCNQ1 and leads to an inability to modulate channel gating and the production of currents that lack the slow activation profile (PMID: 19907016); In silico analysis supports a deleterious effect on protein structure/function; Also known as p.(T59P)/p.(L60P) or p.(T58P)/p.(L59P) (PMID: 9328483, 11530100, 19907016); This variant is associated with the following publications: (PMID: 11530100, 11692163, 26410412, 9328483, 31941373, 19907016, 10973849) -

Jervell and Lange-Nielsen syndrome 2 Pathogenic:1

Nov 01, 1997

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Long QT syndrome Pathogenic:1

Oct 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.172_177delinsCCCCCT, is a complex sequence change that results in the deletion of 2 and insertion of 2 amino acid(s) in the KCNE1 protein (p.Thr58_Leu59delinsProPro). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. This variant has been observed in individuals with Jervell and Lange-Nielsen syndrome and/or long QT syndrome (PMID: 9328483, 10973849, 31941373; internal data). It has also been observed to segregate with disease in related individuals. This variant is also known as T59P/L60P. ClinVar contains an entry for this variant (Variation ID: 132658). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt KCNE1 protein function with a positive predictive value of 95%. Experimental studies have shown that this variant affects KCNE1 function (PMID: 11530100, 19907016). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		6.7
Mutation Taster		=0/200	disease causing

Splicing

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

Other links and lift over

dbSNP: rs281865421; hg19: chr21-35821756;