rs1554105600

Variant names:

• chr6-7555713-C-CT
• rs1554105600
• NM_004415.4:c.171-3dupT

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_004415.4(DSP):​c.171-3dupT variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: DSP NM_004415.4 splice_acceptor, intron
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: -0.595
• Publications: 0 publications found

Genes affected

DSP (HGNC:3052): (desmoplakin) This gene encodes a protein that anchors intermediate filaments to desmosomal plaques and forms an obligate component of functional desmosomes. Mutations in this gene are the cause of several cardiomyopathies and keratodermas, including skin fragility-woolly hair syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

DSP Gene-Disease associations (from GenCC):

• arrhythmogenic right ventricular dysplasia 8

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• keratosis palmoplantaris striata 2

  Inheritance: AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: G2P, Ambry Genetics, Genomics England PanelApp
• skin fragility-woolly hair-palmoplantar keratoderma syndrome

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG, SUPPORTIVE, LIMITED Submitted by: Orphanet, G2P, Genomics England PanelApp, Ambry Genetics
• arrhythmogenic cardiomyopathy with wooly hair and keratoderma

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp, ClinGen, Orphanet, Ambry Genetics
• cardiomyopathy, dilated, with wooly hair, keratoderma, and tooth agenesis

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• lethal acantholytic epidermolysis bullosa

  Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• striate palmoplantar keratoderma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• severe dermatitis-multiple allergies-metabolic wasting syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.011954503 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.2, offset of 0 (no position change), new splice context is: tctgtgtttgcctcctttAGtca. Cryptic site results in inframe 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DSP	NM_004415.4	c.171-3dupT		splice_acceptor_variant, intron_variant	Intron 1 of 23	ENST00000379802.8	NP_004406.2
DSP	NM_001319034.2	c.171-3dupT		splice_acceptor_variant, intron_variant	Intron 1 of 23		NP_001305963.1
DSP	NM_001008844.3	c.171-3dupT		splice_acceptor_variant, intron_variant	Intron 1 of 23		NP_001008844.1
DSP	NM_001406591.1	c.171-3dupT		splice_acceptor_variant, intron_variant	Intron 1 of 10		NP_001393520.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DSP	ENST00000379802.8	c.171-5_171-4insT		splice_region_variant, intron_variant	Intron 1 of 23	1	NM_004415.4	ENSP00000369129.3

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 cardiomyopathy with wooly hair and keratoderma Uncertain:1

May 14, 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 causes a duplication of the 'G' nucleotide at the -3 position in intron 1 of the DSP gene. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with DSP-related disorders in the literature. This variant has not been identified 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 8;C1854063:Arrhythmogenic cardiomyopathy with wooly hair and keratoderma Uncertain:1

Jul 16, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). 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. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. ClinVar contains an entry for this variant (Variation ID: 534301). This variant has not been reported in the literature in individuals affected with DSP-related conditions. This sequence change falls in intron 1 of the DSP gene. It does not directly change the encoded amino acid sequence of the DSP protein. It affects a nucleotide within the consensus splice site. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.59

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: rs1554105600; hg19: chr6-7555946;