rs794728093

Variant names:

• chr18-31524701-AGCTTGAAGGGAT-A
• rs794728093
• NM_001943.5:c.829_840delCTTGAAGGGATG

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM4 PP3 PP5

The NM_001943.5(DSG2):​c.829_840delCTTGAAGGGATG​(p.Leu277_Met280del) variant causes a conservative inframe deletion, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000297 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. It is difficult to determine the true allele frequency of this variant because it is of type DEL_BIG, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000031 (0 hom.)
• Consequence: DSG2 NM_001943.5 conservative_inframe_deletion, splice_region
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:5
• Conservation: PhyloP100: 9.02
• Publications: 0 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: Uncertain_significance. The variant received 4 ACMG points.

• PM4: Nonframeshift variant in NON repetitive region in NM_001943.5.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 18-31524701-AGCTTGAAGGGAT-A is Pathogenic according to our data. Variant chr18-31524701-AGCTTGAAGGGAT-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 199824.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DSG2	NM_001943.5	c.829_840delCTTGAAGGGATG	p.Leu277_Met280del	conservative_inframe_deletion, splice_region_variant	Exon 8 of 15	ENST00000261590.13	NP_001934.2
DSG2	XM_047437315.1	c.295_306delCTTGAAGGGATG	p.Leu99_Met102del	conservative_inframe_deletion, splice_region_variant	Exon 9 of 16		XP_047293271.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DSG2	ENST00000261590.13	c.829-1_839delGCTTGAAGGGAT	p.Leu277fs	frameshift_variant, splice_acceptor_variant, splice_region_variant, intron_variant	Exon 8 of 15	1	NM_001943.5	ENSP00000261590.8

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000294

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00 AC: 0 AN: 249190 AF XY: 0.00

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000315 AC: 46 AN: 1461834 Hom.: 0 AF XY: 0.0000275 AC XY: 20 AN XY: 727214

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

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: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39678

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

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: 0.0000405 AC: 45 AN: 1111994

Other (OTH) AF: 0.0000166 AC: 1 AN: 60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152212 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74376

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41448

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5202

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10630

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000151

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cardiomyopathy Pathogenic:1 Uncertain:1

May 18, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant deletes 12 nucleotides from exon 8 of the DSG2 gene, resulting in an in-frame deletion of 4 amino acids. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in 3 unrelated individuals affected with arrhythmogenic right ventricular cardiomyopathy and it has been observed to segregate with disease in one of the families (PMID: 17105751, 19279339, 23671136). One of these individuals also carried a pathogenic truncation variant in the PKP2 gene that could explain the observed phenotype (PMID: 23671136). This variant has been identified in 1/280596 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. -

Aug 03, 2021

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1 Uncertain:1

Nov 12, 2021

AiLife Diagnostics, AiLife Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 03, 2015

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.829_840del12 mutation has been reported as a disease-causing mutation in association with ARVC (Syrris P et al., 2007, Asimaki A et al., 2009). This mutation was present in a parent and child, both of whom met Task Force criteria for the diagnosis of ARVC. Another child from this family with autopsy-confirmed ARVC also harbored this mutation (Syrris P et al., 2007). The mutation was absent from 200 ethnicity-matched control samples in this study. Furthermore, immunohistochemical analysis of cardiac tissue from autopsy in an individual with this mutation showed marked reduction in immunoreactivity for plakophilin2 and desmoplakin when compared to control tissue (Asimaki A et al., 2009). This mutation results in the deletion of 4 amino acids at the beginning of exon 8, that it is predicted to destroy the normal acceptor site of intron 7 and to create a cryptic splice acceptor site in exon 8. In addition, the NHLBI ESP Exome Variant Server reports c.829_840del12 was not observed in approximately 6,000 samples from individuals of European and African American backgrounds, indicating it is not a common benign variant in these populations. In summary, c.829_840del12 in the DSG2 gene is interpreted as a disease-causing mutation. -

Arrhythmogenic right ventricular cardiomyopathy Uncertain:1

Jul 23, 2024

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 12 nucleotides from exon 8 of the DSG2 gene, resulting in an in-frame deletion of 4 amino acids. Splicing prediction tools suggest that this variant may not disrupt RNA splicing. To our knowledge, functional studies have not been reported for this variant. This variant has been reported to segregate with arrhythmogenic right ventricular cardiomyopathy in a small family (PMID: 17105751), as well as in two unrelated individuals with this condition (PMID: 19279339, 23671136). One of these individuals also carried a pathogenic truncation variant in the PKP2 gene that could explain the observed phenotype (PMID: 23671136). This variant has been identified in 1/280596 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. -

Arrhythmogenic right ventricular dysplasia 10 Uncertain:1

Jan 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant, c.829_840del, results in the deletion of 4 amino acid(s) of the DSG2 protein (p.Leu277_Met280del), but otherwise preserves the integrity of the reading frame. This variant is present in population databases (rs779260860, gnomAD 0.0008%). This variant has been observed in individual(s) with DSG2-related conditions (PMID: 17105751). This variant is also known as c.829-1delGCTTGAAGGGAT (G277fsX278), 829_840delCTTGAAGGCATG. ClinVar contains an entry for this variant (Variation ID: 199824). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

Oct 24, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.829_840del12 variant (also known as p.L277_M280del) is located in coding exon 8 of the DSG2 gene. This variant results from an in-frame CTTGAAGGGATG deletion at nucleotide positions 829 to 840. This results in the deletion of four amino acids between codons 277 and 280. This variant was detected in two related individuals with arrhythmogenic right ventricular cardiomyopathy (ARVC), who shared an additional first degree relative with sudden cardiac death due to ARVC, but who did not have genetic testing (Syrris P et al. Eur. Heart J., 2007 Mar;28:581-8). These amino acid positions are generally not well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.0
Mutation Taster		=3/197	disease causing (ClinVar)

Splicing

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

Other links and lift over

dbSNP: rs794728093; hg19: chr18-29104664;