rs397516687

chr2-219421542-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_001927.4(DES):c.1226T>C(p.Leu409Pro) 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. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. L409L) 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: 7.91

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 hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_001927.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DES	NM_001927.4	c.1226T>C	p.Leu409Pro	missense_variant	6/9	ENST00000373960.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DES	ENST00000373960.4	c.1226T>C	p.Leu409Pro	missense_variant	6/9	1	NM_001927.4	P1
DES	ENST00000477226.6	n.700T>C		non_coding_transcript_exon_variant	5/8	4
DES	ENST00000492726.1	n.621T>C		non_coding_transcript_exon_variant	5/6	4
DES	ENST00000683013.1	n.614T>C		non_coding_transcript_exon_variant	4/7

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 07, 2011

Variant classified as Uncertain Significance - Favor Pathogenic. The Leu409Pro v ariant has not been reported in the literature and has not been previously detec ted in over 254 Caucasian probands tested by our laboratory. Leucine (Leu) at p osition 409 is conserved across mammals and frogs, increasing the likelihood tha t the change is pathogenic. In addition, computational analyses (PolyPhen2, SIFT , AlignGVGD) suggest that the Leu409Pro variant may impact the protein. However, this information is not predictive enough to assume pathogenicity. In summary, evolutionary conservation and computational predictions support a pathogenic rol e but additional studies are necessary to determine the clinical significance of the Leu409Pro variant with certainty. Please note: Desmin variants are assoc iated with a variable clinical phenotype referred to as desmin-related myopathy (OMIM #601419) or myofibrillar myopathy, which can manifest as isolated myopathy (proximal or distal) or isolated cardiomyopathies (including DCM and RCM). Sen sory symptoms (muscle stiffness, aching, and cramps) are present in a small port ion of individuals. Peripheral neuropathy is present in about 20% and cardiomyop athy in 15%-30% of affected individuals. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	34
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.87
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.78	T
M_CAP	Pathogenic	0.59	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.9	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-6.0	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.92		Loss of stability (P = 0.0369);
MVP		0.99
MPC		1.9
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.98
gMVP		0.99

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: rs397516687; hg19: chr2-220286264;