6-7585562-C-T

Position:

• chr6-7585562-C-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_004415.4(DSP):​c.8300C>T​(p.Thr2767Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T2767A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: DSP NM_004415.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:2
• Conservation: PhyloP100: 0.556

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]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1278784).
• BP6: Variant 6-7585562-C-T is Benign according to our data. Variant chr6-7585562-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 629352.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=2, Uncertain_significance=4}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DSP	NM_004415.4	c.8300C>T	p.Thr2767Ile	missense_variant	24/24	ENST00000379802.8
DSP	NM_001319034.2	c.6971C>T	p.Thr2324Ile	missense_variant	24/24
DSP	NM_001008844.3	c.6503C>T	p.Thr2168Ile	missense_variant	24/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DSP	ENST00000379802.8	c.8300C>T	p.Thr2767Ile	missense_variant	24/24	1	NM_004415.4	P2
DSP	ENST00000418664.2	c.6503C>T	p.Thr2168Ile	missense_variant	24/24	1		A2
DSP	ENST00000710359.1	c.6971C>T	p.Thr2324Ile	missense_variant	24/24			A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461876 Hom.: 0 Cov.: 37 AF XY: 0.00000550 AC XY: 4 AN XY: 727238

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 27, 2019

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 isoleucine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with DSP-related conditions. ClinVar contains an entry for this variant (Variation ID: 629352). This variant is not present in population databases (ExAC no frequency). This sequence change replaces threonine with isoleucine at codon 2767 of the DSP protein (p.Thr2767Ile). The threonine residue is moderately conserved and there is a moderate physicochemical difference between threonine and isoleucine. 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. -

Lethal acantholytic epidermolysis bullosa Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Woolly hair-skin fragility syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Arrhythmogenic right ventricular dysplasia 8 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Cardiomyopathy Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 05, 2018

- -

Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 30, 2023

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.42
CADD	Benign	11
DANN	Uncertain	0.97
DEOGEN2	Benign	0.17	T;.
Eigen	Benign	-0.28
Eigen_PC	Benign	-0.24
FATHMM_MKL	Benign	0.47	N
LIST_S2	Benign	0.80	T;T
M_CAP	Benign	0.025	D
MetaRNN	Benign	0.13	T;T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	0.83	L;.
MutationTaster	Benign	0.70	N;N
PrimateAI	Benign	0.41	T
PROVEAN	Benign	-0.23	N;N
REVEL	Benign	0.068
Sift	Benign	0.29	T;T
Sift4G	Benign	0.25	T;T
Polyphen		0.0060	B;.
Vest4		0.12
MutPred		0.29		Loss of disorder (P = 0.053);.;
MVP		0.42
MPC		0.27
ClinPred		0.28	T
GERP RS		2.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.073
gMVP		0.35

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: rs34884895; hg19: chr6-7585795;