rs794728987

Variant names:

• chr2-219420906-C-T
• rs794728987
• NM_001927.4:c.976C>T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP3_Moderate PP5

The NM_001927.4(DES):​c.976C>T​(p.His326Tyr) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,708 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DES NM_001927.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 5.05

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 7 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.849
• PP5: Variant 2-219420906-C-T is Pathogenic according to our data. Variant chr2-219420906-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 201705.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DES	NM_001927.4	c.976C>T	p.His326Tyr	missense_variant	Exon 5 of 9	ENST00000373960.4	NP_001918.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DES	ENST00000373960.4	c.976C>T	p.His326Tyr	missense_variant	Exon 5 of 9	1	NM_001927.4	ENSP00000363071.3
DES	ENST00000477226.6	n.450C>T		non_coding_transcript_exon_variant	Exon 4 of 8	4
DES	ENST00000492726.1	n.371C>T		non_coding_transcript_exon_variant	Exon 4 of 6	4
DES	ENST00000683013.1	n.364C>T		non_coding_transcript_exon_variant	Exon 3 of 7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461708 Hom.: 0 Cov.: 38 AF XY: 0.00000138 AC XY: 1 AN XY: 727146

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: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000936 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Desmin-related myofibrillar myopathy Pathogenic:1

Apr 04, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces histidine, which is basic and polar, with tyrosine, which is neutral and polar, at codon 326 of the DES protein (p.His326Tyr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant DES-related conditions (Invitae). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 201705). 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. For these reasons, this variant has been classified as Pathogenic. -

Cardiomyopathy Uncertain:1

Dec 18, 2020

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Jan 03, 2018

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The H326Y has not been published as a pathogenic variant or as a benign variant to our knowledge. The H326Y variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The H326Y variant is a non-conservative amino acid substitution, which is more likely to impact secondary protein structure as these residues differ in charge, size and/or other properties. This substitution occurs at a position that is conserved across species. In silico analysis predicts this variant is probably damaging to the protein structure/function. Furthermore, a missense variant in a nearby residue (D336Y) has been reported in the Human Gene Mutation Database in association with desmin related myopathy (Stenson et al., 2014).Therefore, additional evidence is needed to determine whether this variant is pathogenic or benign . -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.57
CardioboostCm	Uncertain	0.37
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.2	M
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.5	D
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.63
MutPred		0.62		Loss of disorder (P = 0.1005);
MVP		0.98
MPC		1.4
ClinPred		0.99	D
GERP RS		4.9
Varity_R		0.76
gMVP		0.72

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: rs794728987; hg19: chr2-220285628;