18-30997049-C-A

Position:

• chr18-30997049-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001941.5(DSC3):​c.2236-1G>T variant causes a splice acceptor, intron change. The variant was absent in control chromosomes in GnomAD project. 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 Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: DSC3 NM_001941.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.05

Genes affected

DSC3 (HGNC:3037): (desmocollin 3) The protein encoded by this gene is a calcium-dependent glycoprotein that is a member of the desmocollin subfamily of the cadherin superfamily. These desmosomal family members, along with the desmogleins, are found primarily in epithelial cells where they constitute the adhesive proteins of the desmosome cell-cell junction and are required for cell adhesion and desmosome formation. The desmosomal family members are arranged in two clusters on chromosome 18, occupying less than 650 kb combined. Mutations in this gene are a cause of hypotrichosis and recurrent skin vesicles disorder. The protein can act as an autoantigen in pemphigus diseases, and it is also considered to be a biomarker for some cancers. Alternative splicing of this gene results in multiple transcript variants. [provided by RefSeq, Apr 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.09550353 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.7, offset of -45, new splice context is: gccttctcatgacaacttAGaat. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-30997049-C-A is Pathogenic according to our data. Variant chr18-30997049-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2072986.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DSC3	NM_001941.5	c.2236-1G>T		splice_acceptor_variant, intron_variant		ENST00000360428.9	NP_001932.2
DSC3	NM_024423.4	c.2236-1G>T		splice_acceptor_variant, intron_variant			NP_077741.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DSC3	ENST00000360428.9	c.2236-1G>T		splice_acceptor_variant, intron_variant		1	NM_001941.5	ENSP00000353608.4
DSC3	ENST00000434452.5	c.2236-1G>T		splice_acceptor_variant, intron_variant		5		ENSP00000392068.1
DSC3	ENST00000584980.1	c.358-1G>T		splice_acceptor_variant, intron_variant		5		ENSP00000464283.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 28, 2022

This sequence change affects an acceptor splice site in intron 14 of the DSC3 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 DSC3 are known to be pathogenic (PMID: 18682494, 19765682, 31790667). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DSC3-related conditions. 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 currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	28
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Uncertain	0.96	D
GERP RS		4.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.91		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.91		Position offset: -1

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr18-28577015;