18-31082930-G-T

Position:

• chr18-31082930-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_024422.6(DSC2):​c.1073C>A​(p.Thr358Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign 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. T358I) has been classified as Benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: DSC2 NM_024422.6 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.752

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]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.04611513).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DSC2	NM_024422.6	c.1073C>A	p.Thr358Asn	missense_variant	8/16	ENST00000280904.11	NP_077740.1
DSC2	NM_004949.5	c.1073C>A	p.Thr358Asn	missense_variant	8/17		NP_004940.1
DSC2	NM_001406506.1	c.644C>A	p.Thr215Asn	missense_variant	8/16		NP_001393435.1
DSC2	NM_001406507.1	c.644C>A	p.Thr215Asn	missense_variant	8/17		NP_001393436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DSC2	ENST00000280904.11	c.1073C>A	p.Thr358Asn	missense_variant	8/16	1	NM_024422.6	ENSP00000280904.6
DSC2	ENST00000251081.8	c.1073C>A	p.Thr358Asn	missense_variant	8/17	1		ENSP00000251081.6
DSC2	ENST00000648081.1	c.644C>A	p.Thr215Asn	missense_variant	9/17			ENSP00000497441.1
DSC2	ENST00000682357.1	c.644C>A	p.Thr215Asn	missense_variant	8/16			ENSP00000507826.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 11 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 10, 2022

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with asparagine, which is neutral and polar, at codon 358 of the DSC2 protein (p.Thr358Asn). This variant has not been reported in the literature in individuals affected with DSC2-related conditions. 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. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The asparagine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 519432). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 19, 2017

The p.T358N variant (also known as c.1073C>A), located in coding exon 8 of the DSC2 gene, results from a C to A substitution at nucleotide position 1073. The threonine at codon 358 is replaced by asparagine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species, and asparagine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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
AlphaMissense	Benign	0.071
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.65
CADD	Benign	6.1
DANN	Benign	0.59
DEOGEN2	Benign	0.072	T;.;.
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.99
FATHMM_MKL	Benign	0.10	N
LIST_S2	Benign	0.69	T;T;T
M_CAP	Benign	0.010	T
MetaRNN	Benign	0.046	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.6	L;L;.
PrimateAI	Benign	0.33	T
PROVEAN	Benign	-0.92	N;N;.
REVEL	Benign	0.026
Sift	Benign	0.51	T;T;.
Sift4G	Benign	0.55	T;T;.
Polyphen		0.0	B;B;.
Vest4		0.15
MutPred		0.23		Loss of phosphorylation at T358 (P = 0.0459);Loss of phosphorylation at T358 (P = 0.0459);.;
MVP		0.39
MPC		0.084
ClinPred		0.023	T
GERP RS		1.4
Varity_R		0.11
gMVP		0.43

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: rs139399951; hg19: chr18-28662896;