rs397514042

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PVS1PM2PP3_StrongPP5

The NM_024422.6(DSC2):c.631-2A>G variant causes a splice acceptor change. The variant allele was found at a frequency of 0.000026 in 1,613,508 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

DSC2
NM_024422.6 splice_acceptor

Scores

Splicing: ADA: 1.000

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:10U:3

Conservation

PhyloP100: 4.28

Variant links:

Genes affected

DSC2 (HGNC:3036): (desmocollin 2) This gene encodes a member of the desmocollin protein subfamily. Desmocollins, along with desmogleins, are cadherin-like transmembrane glycoproteins that are major components of the desmosome. Desmosomes are cell-cell junctions that help resist shearing forces and are found in high concentrations in cells subject to mechanical stress. This gene is found in a cluster with other desmocollin family members on chromosome 18. Mutations in this gene are associated with arrhythmogenic right ventricular dysplasia-11, and reduced protein expression has been described in several types of cancer. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Feb 2015]

DSC2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 15 ACMG points.

PVS1

Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.8, offset of 25, new splice context is: tgcctttgcaacaactccAGatg. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 18-31087815-T-C is Pathogenic according to our data. Variant chr18-31087815-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 16850.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=3, Likely_pathogenic=4, Pathogenic=3}. Variant chr18-31087815-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	MANE
DSC2	NM_024422.6 linkuse as main transcript	c.631-2A>G	splice_acceptor_variant	ENST00000280904.11
DSC2	NM_001406506.1 linkuse as main transcript	c.202-2A>G	splice_acceptor_variant
DSC2	NM_001406507.1 linkuse as main transcript	c.202-2A>G	splice_acceptor_variant
DSC2	NM_004949.5 linkuse as main transcript	c.631-2A>G	splice_acceptor_variant

Ensembl

Gene	Transcript	HGVSc	Effect	TSL	MANE	Appris	UniProt
DSC2	ENST00000280904.11 linkuse as main transcript	c.631-2A>G	splice_acceptor_variant	1	NM_024422.6	P1	Q02487-1
DSC2	ENST00000251081.8 linkuse as main transcript	c.631-2A>G	splice_acceptor_variant	1			Q02487-2
DSC2	ENST00000648081.1 linkuse as main transcript	c.202-2A>G	splice_acceptor_variant
DSC2	ENST00000682357.1 linkuse as main transcript	c.202-2A>G	splice_acceptor_variant

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152234

Hom.:

Cov.:

show subpopulations

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

GnomAD3 exomes

AF:

0.0000159

AC:

AN:

251040

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135772

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:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000274

AC:

AN:

1461274

Hom.:

Cov.:

AF XY:

0.0000316

AC XY:

AN XY:

726976

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000360

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152234

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74372

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000669

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:10Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 11

Pathogenic:5

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Dec 09, 2022	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 01, 2006	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 31, 2024	This sequence change affects an acceptor splice site in intron 5 of the DSC2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in DSC2 are known to be pathogenic (PMID: 23911551). This variant is present in population databases (rs397514042, gnomAD 0.004%). Disruption of this splice site has been observed in individual(s) with arrhythmogenic right ventricular cardiomyopathy (PMID: 17186466). ClinVar contains an entry for this variant (Variation ID: 16850). Studies have shown that disruption of this splice site alters mRNA splicing and is expected to lead to the loss of protein expression (PMID: 17186466). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 23, 2020	- -
Likely pathogenic, criteria provided, single submitter	research	UNC Molecular Genetics Laboratory, University of North Carolina at Chapel Hill	-	This variant alters a canonical splice acceptor site in DSC2. This variant has been described previously in the heterozygous state in a patient with autosomal dominant arrhythmogenic right ventricular cardiomyopathy (PMID: 17186466). -

not provided

Pathogenic:4

Pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Sep 07, 2022	Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 32466575, 25390934, 33684294, 32853555, 31402444, 32665702, 23812740, 31872082, 34135346, 33087929, 29788292, 33500567, 17186466) -
Likely pathogenic, criteria provided, single submitter	clinical testing	AiLife Diagnostics, AiLife Diagnostics	Dec 01, 2021	- -
Pathogenic, no assertion criteria provided	clinical testing	Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center	-	- -

Cardiovascular phenotype

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 08, 2023

The c.631-2A>G intronic variant results from an A to G substitution two nucleotides before from coding exon 6 in the DSC2 gene. This variant has been detected in an individual from an arrhythmogenic right ventricular cardiomyopathy (ARVC) cohort with limited clinical detail, and in an individual reported to meet ARVC diagnostic criteria (Baskin B et al. Hum Genet, 2013 Nov;132:1245-52; Heuser A et al. Am J Hum Genet, 2006 Dec;79:1081-8). This variant has also been detected in several cohorts without known ARVC; however, clinical details were often limited (Mazzarotto F et al. Genet Med, 2021 05;23:856-864; Carruth ED et al. Circ Genom Precis Med, 2021 04;14:e003302; Lacaze P et al. NPJ Genom Med, 2021 Jun;6:51; van Rooij J et al. Genet Med, 2020 11;22:1812-1820; Roman TS et al. Am J Hum Genet, 2020 10;107:596-611; Gierman HJ et al. PLoS One, 2014 Nov;9:e112430). In RNA studies by one group, this alteration resulted in aberrant splicing due to use of a cryptic donor site resulting in a frameshift and premature truncation (Heuser A et al. Am J Hum Genet, 2006 Dec;79:1081-8). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -

Cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Feb 28, 2023

This variant alters the canonical splice acceptor site in intron 5 of the DSC2 gene. Computational splicing tools predict that this variant may disrupt splicing. This variant has been reported in two individuals affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 17186466, 23812740). This variant has also been identified in 4/251040 chromosomes in the general population by the Genome Aggregation Database (gnomAD), as well as in a supercentenarian (110 years or older) (PMID: 25390934). Quantitative real-time PCR in cardiac tissue biopsy of an affected individual has shown that this variant leads to aberrant splicing and reduced DSC2 protein levels (PMID: 17186466). Splice and other loss-of-function DSC2 variants have been observed in individuals affected with arrhythmogenic right ventricular cardiomyopathy. Although there is a suspicion for a pathogenic role, clinical significance of loss-of-function DSC2 variants in autosomal dominant arrhythmogenic cardiomyopathy is not yet clearly established. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Arrhythmogenic right ventricular cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Aug 15, 2019

The c.631-2A>G variant in DSC2 has been reported in 2 individuals with ARVC and 1 individual with LVNC (Heuser 2006, LMM data). It was also reported in a 110-year-old individual (Gierman 2014) and in ClinVar (Variation ID: 16850). This variant has been identified in 4/111556 European chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org). This variant occurs in the invariant region (+/- 1,2) of the splice consensus sequence, and in vitro studies confirmed that it leads to aberrant splicing and reduced DSC2 protein levels (Heuser 2006). Splice and other loss-of-function variants in DSC2 have been reported in individuals with ARVC; however, the clinical significance of these variants is not yet fully understood. Although ARVC has primarily been described as a dominant disorder, in several reports of loss-of function variants, only those individuals with a variant on the second allele were affected, suggesting that LOF variants may either act in a recessive manner or have a much milder effect than missense variants. In summary, while there is some suspicion for a pathogenic role in the heterozygous state, the clinical significance of the c.631-2A>G variant, with regard to dominant ARVC is uncertain. ACMG/AMP Criteria applied: PS4_Supporting, PM2, PS3_Moderate. -

Familial isolated arrhythmogenic right ventricular dysplasia

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

Dec 01, 2023

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.55

BayesDel_noAF

Benign

-0.13

Cadd

Pathogenic

Dann

Benign

0.97

Eigen

Pathogenic

0.82

Eigen_PC

Uncertain

0.58

FATHMM_MKL

Pathogenic

0.99

MutationTaster

Benign

1.0

D;D

GERP RS

4.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.76

SpliceAI score (max)

0.99

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.61

Position offset: -27

DS_AL_spliceai

0.99

Position offset: -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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over