2-219421365-G-T

Position:

• chr2-219421365-G-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP3_Moderate

The NM_001927.4(DES):​c.1049G>T​(p.Arg350Leu) 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. R350P) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: DES NM_001927.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.86

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a region_of_interest Interaction with NEB (size 147) in uniprot entity DESM_HUMAN there are 50 pathogenic changes around while only 2 benign (96%) in NM_001927.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-219421365-G-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.902

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DES	NM_001927.4	c.1049G>T	p.Arg350Leu	missense_variant	6/9	ENST00000373960.4	NP_001918.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DES	ENST00000373960.4	c.1049G>T	p.Arg350Leu	missense_variant	6/9	1	NM_001927.4	ENSP00000363071	P1
DES	ENST00000477226.6	n.523G>T		non_coding_transcript_exon_variant	5/8	4
DES	ENST00000492726.1	n.444G>T		non_coding_transcript_exon_variant	5/6	4
DES	ENST00000683013.1	n.437G>T		non_coding_transcript_exon_variant	4/7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Desmin-related myofibrillar myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 26, 2019

This variant is not present in population databases (ExAC 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. This variant disrupts the p.Arg350 amino acid residue in DES. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 15800015, 17439987). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). This variant has not been reported in the literature in individuals with DES-related conditions. This sequence change replaces arginine with leucine at codon 350 of the DES protein (p.Arg350Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
CardioboostCm	Benign	0.066
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Benign	0.85	D
M_CAP	Uncertain	0.18	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.3	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.92
Sift	Benign	0.086	T
Sift4G	Benign	0.072	T
Polyphen		1.0	D
Vest4		0.83
MutPred		0.65		Loss of disorder (P = 0.0475);
MVP		0.99
MPC		1.6
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.54
gMVP		0.81

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: rs57965306; hg19: chr2-220286087; COSMIC: COSV64660407; COSMIC: COSV64660407;