18-31524751-A-T
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 0P and 0B.
The NM_001943.5(DSG2):c.877A>T(p.Ile293Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000595 in 1,614,074 control chromosomes in the GnomAD database, with no homozygous occurrence. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I293V) has been classified as Benign.
Frequency
Consequence
NM_001943.5 missense
Scores
Clinical Significance
Conservation
Publications
- arrhythmogenic right ventricular cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- arrhythmogenic right ventricular dysplasia 10Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- dilated cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
- dilated cardiomyopathy 1BBInheritance: AR Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152212Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.00000802 AC: 2AN: 249370 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000629 AC: 92AN: 1461862Hom.: 0 Cov.: 37 AF XY: 0.0000578 AC XY: 42AN XY: 727230 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152212Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2AN XY: 74368 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Arrhythmogenic right ventricular dysplasia 10 Uncertain:2
This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 293 of the DSG2 protein (p.Ile293Leu). This variant is present in population databases (rs2230234, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with DSG2-related conditions. ClinVar contains an entry for this variant (Variation ID: 36014). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt DSG2 protein function with a negative predictive value of 95%. 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. -
Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3C. Following criteria are met: 0103 - Loss of function and gain of function (the latter with limited evidence, are reported mechanisms of disease in this gene and are associated with arrhythmogenic right ventricular dysplasia 10 (ARVD; MIM#610193) and dilated cardiomyopathy 1BB (DCM; MIM#612877) (ClinVar, PMID: 23071725). (I) 0108 - This gene is associated with both recessive and dominant disease. It is commonly associated with dominant inheritance however, recessive inheritance has been reported in severe DCM patients (OMIM). (I) 0112 - The ARVD condition associated with this gene has incomplete penetrance (OMIM). (I) 0200 - Variant is predicted to result in a missense amino acid change from isoleucine to leucine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v3) <0.001 for a dominant condition (4 heterozygotes, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2) (17,548 heterozygotes, 912 homozygotes). (I) 0504 - Same amino acid change has been observed in placental mammals. (SB) 0600 - Variant is located in the annotated cadherin domain (NCBI). (I) 0709 - Another missense variants comparable to the one identified in this case has previous evidence for being benign. The p.(Ile293Val) is a common polymorphism that has been reported as benign multiple times in ClinVar. (SB) 0808 - Previous reports of pathogenicity for this variant are conflicting. This variant has been reported as likely benign and VUS in ClinVar for cardiomyopathies. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -
not specified Uncertain:1
Variant summary: The DSG2 c.877A>T (p.Ile293Leu) variant causes a missense change involving a conserved nucleotide with 2/4 in silico tools (SNPs&GO not captured due to low reliability index) predict a benign outcome, although these predictions have yet to be functionally assessed. The variant of interest was observed in the large, broad control population, ExAC, with an allele frequency of 2/120730 (1/60365), which exceeds the estimated maximal expected allele frequency for a pathogenic DSG2 variant of 1/100000, however, this observation needs to be cautiously considered due to the cohort potentially harboring phenotypes that could be caused by a DSG2 mutation. The variant of interest, to our knowledge, has not been reported in affected individuals via publications, although a clinical laboratory cites the variant as "likely benign," without additional information for an independent evaluation. Therefore, taking all available lines of evidence into consideration, the variant of interest has been classified as a "Variant of Uncertain Significance (VUS)," until additional information becomes available. -
Cardiomyopathy Uncertain:1
This missense variant replaces isoleucine with leucine at codon 293 of the DSG2 protein. Computational prediction suggests that this variant may not impact protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an infant affected with sudden death (PMID: 37745463 ). This variant has been identified in 3/280772 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different DNA change with the same protein consequence has been reported as a common polymorphism (PMID: 20829228). 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. -
Arrhythmogenic right ventricular cardiomyopathy Uncertain:1
This missense variant replaces isoleucine with leucine at codon 293 of the DSG2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 3/280772 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
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Cardiovascular phenotype Benign:1
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at