2-219421496-G-T

Variant names:

• chr2-219421496-G-T
• rs776786349
• NM_001927.4:c.1180G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_001927.4(DES):​c.1180G>T​(p.Val394Leu) variant causes a missense 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. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V394M) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 31)
• Consequence: DES NM_001927.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02
• Publications: 0 publications found

Genes affected

DES (HGNC:2770): (desmin) This gene encodes a muscle-specific class III intermediate filament. Homopolymers of this protein form a stable intracytoplasmic filamentous network connecting myofibrils to each other and to the plasma membrane. Mutations in this gene are associated with desmin-related myopathy, a familial cardiac and skeletal myopathy (CSM), and with distal myopathies. [provided by RefSeq, Jul 2008]

DES Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1I

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• myofibrillar myopathy 1

  Inheritance: AD, AR, SD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• atrioventricular block

  Inheritance: AD, AR Classification: STRONG Submitted by: Genomics England PanelApp
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: MODERATE Submitted by: ClinGen
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• neurogenic scapuloperoneal syndrome, Kaeser type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 18 uncertain in NM_001927.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 32 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 1.7729 (below the threshold of 3.09). Trascript score misZ: 0.36303 (below the threshold of 3.09). GenCC associations: The gene is linked to myofibrillar myopathy 1, dilated cardiomyopathy 1I, atrioventricular block, arrhythmogenic right ventricular cardiomyopathy, dilated cardiomyopathy, familial isolated dilated cardiomyopathy, neurogenic scapuloperoneal syndrome, Kaeser type.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.923

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DES	NM_001927.4	c.1180G>T	p.Val394Leu	missense_variant	Exon 6 of 9	ENST00000373960.4	NP_001918.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DES	ENST00000373960.4	c.1180G>T	p.Val394Leu	missense_variant	Exon 6 of 9	1	NM_001927.4	ENSP00000363071.3
DES	ENST00000477226.6	n.654G>T		non_coding_transcript_exon_variant	Exon 5 of 8	4
DES	ENST00000492726.1	n.575G>T		non_coding_transcript_exon_variant	Exon 5 of 6	4
DES	ENST00000683013.1	n.568G>T		non_coding_transcript_exon_variant	Exon 4 of 7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000135 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Desmin-related myofibrillar myopathy Uncertain:1

Feb 19, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with DES-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces valine with leucine at codon 394 of the DES protein (p.Val394Leu). The valine residue is highly conserved and there is a small physicochemical difference between valine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
CardioboostCm	Uncertain	0.63
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.75	D
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Uncertain	2.8	M
PhyloP100		8.0
PrimateAI	Pathogenic	0.91	D
PROVEAN	Uncertain	-2.6	D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.029	D
Sift4G	Uncertain	0.029	D
Polyphen		0.99	D
Vest4		0.87
MutPred		0.73		Loss of catalytic residue at V394 (P = 0.0452);
MVP		0.97
MPC		1.1
ClinPred		0.97	D
GERP RS		4.0
Varity_R		0.53
gMVP		0.93
Mutation Taster		=28/72	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: rs776786349; hg19: chr2-220286218;