18-31519866-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 11P and 4B. PM1PM2PM5PP3_StrongPP5BS2

The NM_001943.5(DSG2):​c.145C>T​(p.Arg49Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,872 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R49H) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

DSG2
NM_001943.5 missense

Scores

9
7
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:3

Conservation

PhyloP100: 0.610
Variant links:
Genes affected
DSG2 (HGNC:3049): (desmoglein 2) This gene encodes a member of the desmoglein family and cadherin cell adhesion molecule superfamily of proteins. Desmogleins are calcium-binding transmembrane glycoprotein components of desmosomes, cell-cell junctions between epithelial, myocardial, and other cell types. The encoded preproprotein is proteolytically processed to generate the mature glycoprotein. This gene is present in a gene cluster with other desmoglein gene family members on chromosome 18. Mutations in this gene have been associated with arrhythmogenic right ventricular dysplasia, familial, 10. [provided by RefSeq, Jan 2016]

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 14 uncertain in NM_001943.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr18-31519867-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 16810.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.982
PP5
Variant 18-31519866-C-T is Pathogenic according to our data. Variant chr18-31519866-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 450040.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=3, Likely_pathogenic=2}. Variant chr18-31519866-C-T is described in Lovd as [Likely_pathogenic].
BS2
High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DSG2NM_001943.5 linkc.145C>T p.Arg49Cys missense_variant Exon 3 of 15 ENST00000261590.13 NP_001934.2 Q14126
DSG2XM_047437315.1 linkc.-390C>T 5_prime_UTR_variant Exon 4 of 16 XP_047293271.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DSG2ENST00000261590.13 linkc.145C>T p.Arg49Cys missense_variant Exon 3 of 15 1 NM_001943.5 ENSP00000261590.8 Q14126

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000802
AC:
2
AN:
249476
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135354
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000883
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000342
AC:
5
AN:
1461872
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727236
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000116
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000360
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
ExAC
AF:
0.0000165
AC:
2

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:3
-
Genome Diagnostics Laboratory, University Medical Center Utrecht
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Apr 07, 2025
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Identified in patients with ARVC referred for genetic testing at GeneDx and in published literature (PMID: 27532257); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 31402444, 16773573, 27532257) -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

Cardiomyopathy Pathogenic:1
Nov 13, 2024
Color Diagnostics, LLC DBA Color Health
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces arginine with cysteine at codon 49 in the propeptide sequence domain of the DSG2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function. This variant changes an arginine residue at the highly conserved propeptide cleavage motif. Missense variants affecting this motif have been shown to prevent N-terminal propeptide cleavage and alter the adhesive properties of the DSG2 protein (PMID: 16773573, 23071725, 23381804, 31845994). Although functional studies have not been reported for this variant, it is expected to disrupt DSG2 protein function. This variant has been reported in three individuals affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 27532257; ClinVar SCV001953892.1, SCV000618572.2). This variant has been identified in 2/249476 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different missense variant occurring at the same codon, p.Arg49His, is known to cause arrhythmogenic right ventricular cardiomyopathy (ClinVar variation ID 16810), indicating that arginine at this position is important for DSG2 protein function. This variant has been identified in 2/249476 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Based on the available evidence, this variant is classified as Likely Pathogenic. -

Arrhythmogenic right ventricular cardiomyopathy Uncertain:1
Jun 28, 2023
All of Us Research Program, National Institutes of Health
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This missense variant replaces arginine with cysteine at codon 49 of the DSG2 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 27532257). This variant has been identified in 2/249476 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different missense variant occurring at the same codon, p.Arg49His, is known to cause arrhythmogenic right ventricular cardiomyopathy (Clinvar variation ID 16810), indicating that arginine at this position is important for DSG2 protein function. 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 dysplasia 10 Uncertain:1
Jan 21, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This variant is present in population databases (rs762526848, gnomAD 0.003%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 49 of the DSG2 protein (p.Arg49Cys). This missense change has been observed in individual(s) with clinical features of DSG2-related conditions (PMID: 27532257). 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 variant disrupts the p.Arg49 amino acid residue in DSG2. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 19151369, 19863551, 20400443). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 450040). -

Cardiovascular phenotype Uncertain:1
Oct 30, 2024
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.R49C variant (also known as c.145C>T), located in coding exon 3 of the DSG2 gene, results from a C to T substitution at nucleotide position 145. The arginine at codon 49 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant has been reported in a large study of pathogenicity of Mendelian variants in cardiomyopathy patients, but clinical details are limited (Walsh R et al. Genet Med, 2017 Feb;19:192-203). Another variant at the same codon, p.R49H (c.146G>A), has been described in association with arrhythmogenic right ventricular cardiomyopathy (ARVC). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.95
BayesDel_addAF
Pathogenic
0.31
D
BayesDel_noAF
Pathogenic
0.30
CADD
Uncertain
24
DANN
Benign
0.95
DEOGEN2
Uncertain
0.77
D;D
Eigen
Uncertain
0.39
Eigen_PC
Benign
0.21
FATHMM_MKL
Uncertain
0.84
D
LIST_S2
Uncertain
0.92
D;D
M_CAP
Uncertain
0.25
D
MetaRNN
Pathogenic
0.98
D;D
MetaSVM
Uncertain
0.54
D
MutationAssessor
Pathogenic
3.9
H;.
PrimateAI
Uncertain
0.63
T
PROVEAN
Pathogenic
-7.5
D;.
REVEL
Pathogenic
0.77
Sift
Pathogenic
0.0
D;.
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;.
Vest4
0.79
MutPred
0.88
Loss of MoRF binding (P = 0.0045);Loss of MoRF binding (P = 0.0045);
MVP
0.92
MPC
0.49
ClinPred
1.0
D
GERP RS
2.3
Varity_R
0.53
gMVP
0.95

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.030
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs762526848; hg19: chr18-29099829; COSMIC: COSV55196659; API