rs774739275

Positions:

• chr2-219420311-G-A
• chr2-219420311-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001927.4(DES):​c.700G>A​(p.Glu234Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,850 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. E234E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: DES NM_001927.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• 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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.905

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DES	NM_001927.4	c.700G>A	p.Glu234Lys	missense_variant	3/9	ENST00000373960.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DES	ENST00000373960.4	c.700G>A	p.Glu234Lys	missense_variant	3/9	1	NM_001927.4	P1
DES	ENST00000477226.6	n.174G>A		non_coding_transcript_exon_variant	2/8	4
DES	ENST00000492726.1	n.95G>A		non_coding_transcript_exon_variant	2/6	4
DES	ENST00000683013.1	n.88G>A		non_coding_transcript_exon_variant	1/7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461850 Hom.: 0 Cov.: 36 AF XY: 0.00000688 AC XY: 5 AN XY: 727222

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: 0.00

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000259 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Desmin-related myofibrillar myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 24, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 234 of the DES protein (p.Glu234Lys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with DES-related conditions. ClinVar contains an entry for this variant (Variation ID: 411150). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on DES protein function. 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 specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Apr 24, 2023

Variant summary: DES c.700G>A (p.Glu234Lys) results in a conservative amino acid change located in the Intermediate filament, rod domain (IPR039008) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 251444 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.700G>A has been reported in the literature in one individual affected with Cardiomyopathy, however this individual also carried variants of uncertain significance in other genes (MYPN and CACNA1C) that may contribute to the observed phenotype (Chen_2017). Therefore, this report does not provide unequivocal conclusions about association of the variant with Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One ClinVar submitter has assessed the variant since 2014: the variant was classified as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
CardioboostCm	Uncertain	0.81
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.81	D
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.8	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.3	D
REVEL	Pathogenic	0.87
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.038	D
Polyphen		1.0	D
Vest4		0.78
MutPred		0.71		Gain of MoRF binding (P = 0.0141);
MVP		0.99
MPC		1.5
ClinPred		1.0	D
GERP RS		4.4
Varity_R		0.79
gMVP		0.90

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: rs774739275; hg19: chr2-220285033;