chr18-31536238-T-C

Position:

• chr18-31536238-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_001943.5(DSG2):​c.1460T>C​(p.Ile487Thr) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. I487S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: DSG2 NM_001943.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 6.16

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DSG2	NM_001943.5	c.1460T>C	p.Ile487Thr	missense_variant	11/15	ENST00000261590.13
DSG2	XM_047437315.1	c.926T>C	p.Ile309Thr	missense_variant	12/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DSG2	ENST00000261590.13	c.1460T>C	p.Ile487Thr	missense_variant	11/15	1	NM_001943.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Jul 19, 2023

Variant of Uncertain Significance due to insufficient evidence: This missense variant is located in the extracellular cadherin domain 4 of the DSG2 protein. Computational prediction tools and conservation analyses are inconclusive regarding the impact of this variant on the protein function. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant nor has this variant been reported in individuals affected with cardiovascular disorders in the literature. This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the pathogenicity of this variant conclusively. -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Jul 06, 2023

This missense variant replaces isoleucine with threonine at codon 487 of the DSG2 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 not been reported in individuals affected with DSG2-related disorders in the literature. This variant has not been identified 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. -

Arrhythmogenic right ventricular dysplasia 10 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 18, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 487 of the DSG2 protein (p.Ile487Thr). This variant is not present in population databases (gnomAD no frequency). 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: 191631). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt DSG2 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. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Jun 24, 2013

- -

Arrhythmogenic right ventricular dysplasia 10;C2752072:Dilated cardiomyopathy 1BB Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Sep 03, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.64	D
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.35
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Uncertain	0.12	D
MutationAssessor	Pathogenic	3.8	H
MutationTaster	Benign	0.99	N
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-3.9	D
REVEL	Uncertain	0.55
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.99	D
Vest4		0.73
MutPred		0.72		Loss of stability (P = 0.0035);
MVP		0.91
MPC		0.43
ClinPred		0.93	D
GERP RS		5.9
Varity_R		0.50
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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

Other links and lift over

dbSNP: rs776525113; hg19: chr18-29116201;