rs199473031
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 1P and 5B. PP2BP4BS2
The NM_000238.4(KCNH2):c.3322C>G(p.Leu1108Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00003 in 1,598,314 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
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 -4 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| KCNH2 | NM_000238.4 | c.3322C>G | p.Leu1108Val | missense_variant | Exon 14 of 15 | ENST00000262186.10 | NP_000229.1 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152124Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000578 AC: 14AN: 242114 AF XY: 0.0000919 show subpopulations
GnomAD4 exome AF: 0.0000318 AC: 46AN: 1446190Hom.: 2 Cov.: 32 AF XY: 0.0000474 AC XY: 34AN XY: 716900 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152124Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74312 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Long QT syndrome 2 Uncertain:2
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
The missense c.3322C>Gp.Leu1108Val variant in KCNH2 gene has been reported previously in individuals affected with long QT syndrome Koo SH, et al., 2006. The p.Leu1108Val variant has been reported with allele frequency of 0.006% in gnomAD Exomes and is novel not in any individuals in 1000 Genomes. This variant has been reported to the ClinVar database as Likely Benign / Uncertain Significance multiple submissions. The amino acid change p.Leu1108Val in KCNH2 is predicted as conserved by GERP++ and PhyloP across 100 vertebrates. The amino acid Leu at position 1108 is changed to a Val changing protein sequence and it might alter its composition and physico-chemical properties. For these reasons, this variant has been classified as a Variant of Uncertain Significance VUS. -
Long QT syndrome Uncertain:1
This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1108 of the KCNH2 protein (p.Leu1108Val). This variant is present in population databases (rs199473031, gnomAD 0.05%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with KCNH2-related conditions. ClinVar contains an entry for this variant (Variation ID: 67488). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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. -
Cardiovascular phenotype Uncertain:1
The c.3322C>G (p.L1108V) alteration is located in exon 14 (coding exon 14) of the KCNH2 gene. This alteration results from a C to G substitution at nucleotide position 3322, causing the leucine (L) at amino acid position 1108 to be replaced by a valine (V). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -
Cardiac arrhythmia Benign:1
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not provided Other:1
This variant has been reported in the following publications (PMID:16487223). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at