rs199473438
Variant summary
Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PP2PP3BS2
The NM_000238.4(KCNH2):c.2758C>T(p.Arg920Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000144 in 1,529,092 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R920Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_000238.4 missense
Scores
Clinical Significance
Conservation
Publications
- long QT syndromeInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- long QT syndrome 2Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
- short QT syndromeInheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
- short QT syndrome type 1Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- Brugada syndromeInheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp
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ACMG classification
Our verdict: Likely_benign. The variant received -2 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| KCNH2 | NM_000238.4 | c.2758C>T | p.Arg920Trp | missense_variant | Exon 12 of 15 | ENST00000262186.10 | NP_000229.1 |
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| KCNH2 | ENST00000262186.10 | c.2758C>T | p.Arg920Trp | missense_variant | Exon 12 of 15 | 1 | NM_000238.4 | ENSP00000262186.5 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152062Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000797 AC: 1AN: 125518 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000138 AC: 19AN: 1377030Hom.: 0 Cov.: 36 AF XY: 0.0000147 AC XY: 10AN XY: 678700 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152062Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74288 show subpopulations
ClinVar
Submissions by phenotype
Long QT syndrome Uncertain:2
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 920 of the KCNH2 protein (p.Arg920Trp). 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 missense change has been observed in individual(s) with clinical features of KCNH2-related conditions (PMID: 19716085, 36861347). ClinVar contains an entry for this variant (Variation ID: 67433). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The tryptophan amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
This missense variant replaces arginine with tryptophan at codon 920 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic test (PMID: 19716085). This variant has been identified in 1/125518 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
not provided Uncertain:1
KCNH2: PM5, PM2:Supporting, PP2 -
Cardiovascular phenotype Uncertain:1
The c.2758C>T (p.R920W) alteration is located in exon 12 (coding exon 12) of the KCNH2 gene. This alteration results from a C to T substitution at nucleotide position 2758, causing the arginine (R) at amino acid position 920 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Cardiac arrhythmia Uncertain:1
This missense variant replaces arginine with tryptophan at codon 920 of the KCNH2 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual referred for long QT syndrome genetic test (PMID: 19716085). This variant has been identified in 1/125518 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Congenital long QT syndrome Other:1
This variant has been reported as associated with Long QT syndrome in the following publications (PMID:19716085). 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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at