chr6-7565521-G-T

Variant names:

• chr6-7565521-G-T
• rs727504443
• NM_004415.4:c.939+1G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_004415.4(DSP):​c.939+1G>T variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. 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 Pathogenic (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: DSP NM_004415.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.86
• 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: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.01880223 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-7565521-G-T is Pathogenic according to our data. Variant chr6-7565521-G-T is described in ClinVar as Pathogenic. ClinVar VariationId is 1076116.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004415.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DSP	NM_004415.4	MANE Select	c.939+1G>T		splice_donor intron	N/A	NP_004406.2
	DSP	NM_001319034.2		c.939+1G>T		splice_donor intron	N/A	NP_001305963.1
	DSP	NM_001008844.3		c.939+1G>T		splice_donor intron	N/A	NP_001008844.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	DSP	ENST00000379802.8	TSL:1 MANE Select	c.939+1G>T		splice_donor intron	N/A	ENSP00000369129.3
	DSP	ENST00000418664.3	TSL:1	c.939+1G>T		splice_donor intron	N/A	ENSP00000396591.2
	DSP	ENST00000506617.1	TSL:3	n.458G>T		non_coding_transcript_exon	Exon 4 of 4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Arrhythmogenic right ventricular dysplasia 8;C1854063:Arrhythmogenic cardiomyopathy with wooly hair and keratoderma Pathogenic:1

Nov 15, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site results in intron 7 inclusion and introduces a premature termination codon (PMID: 10594734). The resulting mRNA is expected to undergo nonsense-mediated decay. ClinVar contains an entry for this variant (Variation ID: 1076116). Disruption of this splice site has been observed in individuals with clinical features of DSP-related conditions (PMID: 10594734, 20864495; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 7 of the DSP gene. RNA analysis indicates that disruption of this splice site induces altered splicing and may result in an absent or disrupted protein product.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	32
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		9.9
GERP RS		5.5
Mutation Taster		=0/100	disease causing

Splicing

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

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

Other links and lift over

dbSNP: rs727504443; hg19: chr6-7565754; COSMIC: COSV65791640;