chr11-2588804-C-T
Variant summary
Our verdict is Uncertain significance. The variant received -1 ACMG points: 0P and 1B. BS4_Supporting
This summary comes from the ClinGen Evidence Repository: NM_000218.3(KCNQ1):c.1343C>T is a missense variant ithat substitutes proline with leucine at codon 448 (p.Pro448Leu). This variant is present in gnomAD v.4.1.0 at a maximum allele frequency of 0.00005254, with 62 alleles / 1,179,942 total alleles in the European non-Finnish population, which is higher than the ClinGen Potassium Channel Arrhythmia VCEP PM2_Supporting threshold of <0.00001, but lower than the BS1 threshold of >0.0004 so neither criterion is met. This variant has been reported in at least 1 proband affected with long QT syndrome 1, however, the requirement for 2 unrelated probands has not been reached so the PS4_Supporting code is not yet met (PMID:23392653, PMID:19716085, PMID:25854863). The variant has been observed in a family with long QT syndrome but fails to segregate with the disease phenotype in at least 1 affected member (PMID:23392653; BS4_Supporting). The computational predictor REVEL gives a score of 0.592, which is below the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.75 but higher than the BP4 threshold of <0.25 and does not strongly predict a damaging effect on KCNQ1 function. The computational splicing predictor SpliceAI gives a score of 0.00, which is lower than the ClinGen Potassium Channel Arrhythmia VCEP PP3 threshold of >0.5 and does not strongly predict a damaging effect on KCNQ1 splicing. In summary, this variant meets the criteria to be classified as a variant of uncertain significance for long QT syndrome 1 based on the ACMG/AMP criteria applied, as specified by the ClinGen Potassium Channel Arrhythmia VCEP: BS4_Supporting. (VCEP specifications version 1.0.0; date of approval 03/04/2025). LINK:https://erepo.genome.network/evrepo/ui/classification/CA005629/MONDO:0100316/112
Frequency
Consequence
NM_000218.3 missense
Scores
Clinical Significance
Conservation
Publications
- long QT syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- long QT syndrome 1Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- Jervell and Lange-Nielsen syndromeInheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
- Jervell and Lange-Nielsen syndrome 1Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
- atrial fibrillation, familial, 3Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
- short QT syndromeInheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
- short QT syndrome type 2Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
- familial atrial fibrillationInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Jervell and Lange-Nielsen syndromeInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hypertrophic cardiomyopathyInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received -1 ACMG points.
Variant Effect in Transcripts
ACMG analysis was done for transcript: NM_000218.3. You can select a different transcript below to see updated ACMG assignments.
RefSeq Transcripts
Ensembl Transcripts
| Sel. | Gene | Transcript | Tags | HGVSc | HGVSp | Effect | Exon Rank | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|---|
| KCNQ1 | TSL:1 MANE Select | c.1343C>T | p.Pro448Leu | missense | Exon 10 of 16 | ENSP00000155840.2 | P51787-1 | ||
| KCNQ1 | TSL:1 | c.962C>T | p.Pro321Leu | missense | Exon 10 of 16 | ENSP00000334497.5 | P51787-2 | ||
| KCNQ1 | c.1340C>T | p.Pro447Leu | missense | Exon 10 of 16 | ENSP00000581056.1 |
Frequencies
GnomAD3 genomes AF: 0.0000592 AC: 9AN: 152086Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000200 AC: 5AN: 250376 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000376 AC: 55AN: 1461180Hom.: 0 Cov.: 32 AF XY: 0.0000371 AC XY: 27AN XY: 726868 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000592 AC: 9AN: 152086Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74286 show subpopulations
Age Distribution
ClinVar
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at