rs199472874
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 1P and 4B. PP2BS2
The NM_000238.4(KCNH2):c.754C>T(p.Arg252Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,371,584 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R252P) 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 -3 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| KCNH2 | NM_000238.4 | c.754C>T | p.Arg252Trp | missense_variant | Exon 4 of 15 | ENST00000262186.10 | NP_000229.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000659 AC: 1AN: 151846Hom.: 0 Cov.: 33 show subpopulations
GnomAD4 exome AF: 0.0000115 AC: 14AN: 1219738Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 8AN XY: 594704 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000659 AC: 1AN: 151846Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1AN XY: 74182 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Long QT syndrome Uncertain:1
This sequence change replaces arginine with tryptophan at codon 252 of the KCNH2 protein (p.Arg252Trp). The arginine residue is weakly conserved and there is a moderate physicochemical difference between arginine and tryptophan. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at