NM_004415.4:c.922A>C

Variant names:

• chr6-7565503-A-C
• rs1060500617
• NM_004415.4:c.922A>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_004415.4(DSP):​c.922A>C​(p.Lys308Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: DSP NM_004415.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.20
• 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 2 ACMG points.

• 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.922A>C	p.Lys308Gln	missense_variant	Exon 7 of 24	ENST00000379802.8	NP_004406.2
DSP	NM_001319034.2	c.922A>C	p.Lys308Gln	missense_variant	Exon 7 of 24		NP_001305963.1
DSP	NM_001008844.3	c.922A>C	p.Lys308Gln	missense_variant	Exon 7 of 24		NP_001008844.1
DSP	NM_001406591.1	c.922A>C	p.Lys308Gln	missense_variant	Exon 7 of 11		NP_001393520.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DSP	ENST00000379802.8	c.922A>C	p.Lys308Gln	missense_variant	Exon 7 of 24	1	NM_004415.4	ENSP00000369129.3

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251222 AF XY: 0.00000737

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Jul 23, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with glutamine, which is neutral and polar, at codon 308 of the DSP protein (p.Lys308Gln). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with DSP-related conditions. ClinVar contains an entry for this variant (Variation ID: 405243). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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. -

not provided Uncertain:1

Apr 04, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Cardiovascular phenotype Uncertain:1

Mar 09, 2020

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.K308Q variant (also known as c.922A>C), located in coding exon 7 of the DSP gene, results from an A to C substitution at nucleotide position 922. The lysine at codon 308 is replaced by glutamine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.79	D;.
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.91	D;D
M_CAP	Uncertain	0.24	D
MetaRNN	Uncertain	0.62	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.7	M;M
PhyloP100		9.2
PrimateAI	Uncertain	0.70	T
PROVEAN	Uncertain	-3.5	D;D
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.51
MutPred		0.42		Loss of ubiquitination at K308 (P = 0.0071);Loss of ubiquitination at K308 (P = 0.0071);
MVP		0.94
MPC		0.85
ClinPred		0.98	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.84
gMVP		0.66
Mutation Taster		=30/70	disease causing

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: rs1060500617; hg19: chr6-7565736;