11-2588718-GAAAA-GAAA
Variant summary
Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_000218.3(KCNQ1):c.1265delA(p.Lys422SerfsTer10) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000868 in 1,613,158 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000218.3 frameshift
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 16 ACMG points.
Transcripts
RefSeq
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|---|
KCNQ1 | ENST00000155840.12 | c.1265delA | p.Lys422SerfsTer10 | frameshift_variant | Exon 10 of 16 | 1 | NM_000218.3 | ENSP00000155840.2 | ||
KCNQ1 | ENST00000335475.6 | c.884delA | p.Lys295SerfsTer10 | frameshift_variant | Exon 10 of 16 | 1 | ENSP00000334497.5 | |||
KCNQ1 | ENST00000496887.7 | c.908delA | p.Lys303SerfsTer10 | frameshift_variant | Exon 10 of 16 | 5 | ENSP00000434560.2 | |||
KCNQ1 | ENST00000646564.2 | c.725delA | p.Lys242SerfsTer10 | frameshift_variant | Exon 5 of 11 | ENSP00000495806.2 |
Frequencies
GnomAD3 genomes AF: 0.00000658 AC: 1AN: 151936Hom.: 0 Cov.: 33
GnomAD4 exome AF: 0.00000890 AC: 13AN: 1461222Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4AN XY: 726892
GnomAD4 genome AF: 0.00000658 AC: 1AN: 151936Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74198
ClinVar
Submissions by phenotype
not provided Pathogenic:5
Reported in association with sinus bradycardia and LQTS or suspected LQTS (Lupoglazoff et al., 2004; Kapa et al., 2009; Barsheshet et al., 2012; Stattin et al., 2012; Diebold et al., 2020); Not observed at significant frequency in large population cohorts (gnomAD); Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 23098067, 19716085, 32048431, 32421437, 30847666, 34505893, 22456477, 14998624, 19841300) -
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KCNQ1: PVS1, PM2, PS4:Moderate -
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Long QT syndrome Pathogenic:3
This variant deletes 1 nucleotide in exon 10 of the KCNQ1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in several individuals affected with long QT syndrome (PMID: 19716085, 19841300, 22456477, 23098067). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease. Based on available evidence, this variant is classified as Pathogenic. -
Variant summary: KCNQ1 c.1265delA (p.Lys422SerfsX10) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 1.2e-05 in 250000 control chromosomes. c.1265delA has been reported in the literature in individuals affected with Long QT Syndrome (Kapplinger_2009). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Eight clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
This sequence change creates a premature translational stop signal (p.Lys422Serfs*10) in the KCNQ1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in KCNQ1 are known to be pathogenic (PMID: 9323054, 19862833). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individual(s) with long QT syndrome (PMID: 14998624, 19716085, 19841300, 22456477, 23098067). ClinVar contains an entry for this variant (Variation ID: 52973). For these reasons, this variant has been classified as Pathogenic. -
Long QT syndrome 1 Pathogenic:1
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Cardiovascular phenotype Pathogenic:1
The c.1265delA (p.K422Sfs*10) alteration, located in exon 10 (coding exon 10) of the KCNQ1 gene, consists of a deletion of one nucleotide at position 1265, causing a translational frameshift with a predicted alternate stop codon after 10 amino acids. This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. for KCNQ1-related long QT syndrome; however, it is unlikely to be causative of KCNQ1-related short QT syndrome. Based on data from gnomAD, this allele has an overall frequency of 0.001% (3/250000) total alleles studied. The highest observed frequency was 0.006% (1/16132) of African alleles. This variant has been reported in the heterozygous state in multiple individuals with features consistent with long QT syndrome (Kapa, 2009; Kapplinger, 2009; van Lint 2019; Mazzaccara, 2022). This variant has also been identified in the compound heterozygous state in at least one individual with clinical features consistent with autosomal recessive Jervell and Lange-Nielsen syndrome (Zhao, 2023). Based on the available evidence, this alteration is classified as pathogenic. -
Cardiac arrhythmia Pathogenic:1
This variant deletes 1 nucleotide in exon 10 of the KCNQ1 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in several individuals affected with long QT syndrome (PMID: 19716085, 19841300, 22456477, 23098067). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Loss of KCNQ1 function is a known mechanism of disease. Based on available evidence, this variant is classified as Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at