2-219420925-C-T

Variant names:

• chr2-219420925-C-T
• rs368453327
• NM_001927.4:c.995C>T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_001927.4(DES):​c.995C>T​(p.Thr332Ile) variant causes a missense change. The variant allele was found at a frequency of 0.00000753 in 1,461,320 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 (★★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: DES NM_001927.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.00

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 6 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, 0.916

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DES	NM_001927.4	c.995C>T	p.Thr332Ile	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.995C>T	p.Thr332Ile	missense_variant	Exon 5 of 9	1	NM_001927.4	ENSP00000363071.3
DES	ENST00000477226.6	n.469C>T		non_coding_transcript_exon_variant	Exon 4 of 8	4
DES	ENST00000492726.1	n.390C>T		non_coding_transcript_exon_variant	Exon 4 of 6	4
DES	ENST00000683013.1	n.383C>T		non_coding_transcript_exon_variant	Exon 3 of 7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 0.00000753 AC: 11 AN: 1461320 Hom.: 0 Cov.: 38 AF XY: 0.00000825 AC XY: 6 AN XY: 726942

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: 0.00000990

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

Alfa AF: 0.0000329 Hom.: 0

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 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

Apr 05, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 332 of the DES protein (p.Thr332Ile). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. 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: 575152). 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. -

Cardiovascular phenotype Uncertain:1

Oct 17, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.T332I variant (also known as c.995C>T), located in coding exon 5 of the DES gene, results from a C to T substitution at nucleotide position 995. The threonine at codon 332 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
CardioboostCm	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.89	D
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.94	D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	0.87	D
MutationAssessor	Uncertain	2.8	M
PrimateAI	Pathogenic	0.79	T
PROVEAN	Pathogenic	-4.8	D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.99	D
Vest4		0.82
MVP		0.99
MPC		1.5
ClinPred		0.99	D
GERP RS		4.9
Varity_R		0.88
gMVP		0.80

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: rs368453327; hg19: chr2-220285647;