NM_001943.5:c.1773_1774delTG

Variant names:

• chr18-31538869-TTG-T
• rs397516703
• NM_001943.5:c.1773_1774delTG

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PVS1 PP5

The NM_001943.5(DSG2):​c.1773_1774delTG​(p.Cys591fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,770 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: DSG2 NM_001943.5 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5 U:1
• Conservation: PhyloP100: 7.63
• Publications: 4 publications found

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]

DSG2 Gene-Disease associations (from GenCC):

• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• arrhythmogenic right ventricular dysplasia 10

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• dilated cardiomyopathy 1BB

  Inheritance: AR Classification: LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 18-31538869-TTG-T is Pathogenic according to our data. Variant chr18-31538869-TTG-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 44286.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DSG2	NM_001943.5	c.1773_1774delTG	p.Cys591fs	frameshift_variant	Exon 12 of 15	ENST00000261590.13	NP_001934.2
DSG2	XM_047437315.1	c.1239_1240delTG	p.Cys413fs	frameshift_variant	Exon 13 of 16		XP_047293271.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DSG2	ENST00000261590.13	c.1773_1774delTG	p.Cys591fs	frameshift_variant	Exon 12 of 15	1	NM_001943.5	ENSP00000261590.8

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249168 AF XY: 0.00000740

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461770 Hom.: 0 AF XY: 0.00000688 AC XY: 5 AN XY: 727204

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000809 AC: 9 AN: 1111900

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:5 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:2

Jul 12, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; A different nucleotide change (c.1773 T>A) leading to the same nonsense variant has been reported in HGMD (Stenson et al., 2014); This variant is associated with the following publications: (PMID: 27535533, 31402444, 25157032, 21606390, 17105751, 19279339, 19095136) -

Jan 19, 2022

AiLife Diagnostics, AiLife Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Arrhythmogenic right ventricular cardiomyopathy Pathogenic:1 Uncertain:1

Apr 23, 2018

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Dec 18, 2023

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant deletes 2 nucleotides in exon 12 of the DSG2 gene, creating a frameshift and premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least three unrelated individuals affected with arrhythmogenic cardiomyopathy (PMID: 17105751, 19095136, 25157032) and has been shown to segregate with disease in two families (PMID: 17105751, 25157032). The p.Cys591* variant has been identified in a 45 year old patient with ARVC (PMID: 19279339). This variant has been identified in 1/249168 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Although there is a suspicion that this variant may be associated with disease, additional studies are necessary 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 Pathogenic:1

Jul 29, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 44286). This premature translational stop signal has been observed in individual(s) with clinical features of DSG2-related conditions (PMID: 17105751). This variant is present in population databases (rs774105846, gnomAD 0.0009%). This sequence change creates a premature translational stop signal (p.Cys591*) in the DSG2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in DSG2 are known to be pathogenic (PMID: 17105751, 31386562). -

Cardiovascular phenotype Pathogenic:1

Jan 03, 2025

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1773_1774delTG pathogenic mutation, located in coding exon 12 of the DSG2 gene, results from a deletion of two nucleotides at nucleotide positions 1773 to 1774, causing a translational frameshift with a predicted alternate stop codon (p.C591*). This variant was reported in individual(s) with features consistent with arrhythmogenic right ventricular cardiomyopathy (ARVC) (Syrris P et al. Eur Heart J, 2007 Mar;28:581-8; Brun F et al. J Med Genet, 2014 Oct;51:669-76). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.6
Mutation Taster		=2/198	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs397516703; hg19: chr18-29118832;