rs368343125

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_003803.4(MYOM1):c.919C>T(p.Arg307Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000174 in 1,613,232 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R307H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 7.38

Variant links:

Genes affected

MYOM1 (HGNC:7613): (myomesin 1) The giant protein titin, together with its associated proteins, interconnects the major structure of sarcomeres, the M bands and Z discs. The C-terminal end of the titin string extends into the M line, where it binds tightly to M-band constituents of apparent molecular masses of 190 kD (myomesin 1) and 165 kD (myomesin 2). This protein, myomesin 1, like myomesin 2, titin, and other myofibrillar proteins contains structural modules with strong homology to either fibronectin type III (motif I) or immunoglobulin C2 (motif II) domains. Myomesin 1 and myomesin 2 each have a unique N-terminal region followed by 12 modules of motif I or motif II, in the arrangement II-II-I-I-I-I-I-II-II-II-II-II. The two proteins share 50% sequence identity in this repeat-containing region. The head structure formed by these 2 proteins on one end of the titin string extends into the center of the M band. The integrating structure of the sarcomere arises from muscle-specific members of the superfamily of immunoglobulin-like proteins. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jul 2008]

MYOM1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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, 0.868

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYOM1	NM_003803.4 linkuse as main transcript	c.919C>T	p.Arg307Cys	missense_variant	5/38	ENST00000356443.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYOM1	ENST00000356443.9 linkuse as main transcript	c.919C>T	p.Arg307Cys	missense_variant	5/38	1	NM_003803.4	P2	P52179-1
MYOM1	ENST00000261606.11 linkuse as main transcript	c.919C>T	p.Arg307Cys	missense_variant	5/37	1		A2	P52179-2

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152114

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000145

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000482

AC:

AN:

249004

Hom.:

AF XY:

0.0000518

AC XY:

AN XY:

135094

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.0000290

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000982

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000531

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000151

AC:

AN:

1461118

Hom.:

Cov.:

AF XY:

0.0000220

AC XY:

AN XY:

726820

show subpopulations

Gnomad4 AFR exome

AF:

0.000120

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000464

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000990

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152114

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74304

show subpopulations

Gnomad4 AFR

AF:

0.000145

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000645

Hom.:

Bravo

AF:

0.0000416

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000121

AC:

ExAC

AF:

0.0000414

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 05, 2023

The p.R307C variant (also known as c.919C>T), located in coding exon 4 of the MYOM1 gene, results from a C to T substitution at nucleotide position 919. The arginine at codon 307 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is conserved. 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. -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 28, 2023

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. 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) performed at Invitae indicates that this missense variant is not expected to disrupt MYOM1 protein function. ClinVar contains an entry for this variant (Variation ID: 576075). This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. This variant is present in population databases (rs368343125, gnomAD 0.01%). This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 307 of the MYOM1 protein (p.Arg307Cys). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.55

BayesDel_addAF

Uncertain

0.11

BayesDel_noAF

Pathogenic

0.16

Cadd

Pathogenic

Dann

Uncertain

1.0

DEOGEN2

Benign

0.33

T;.;.

Eigen

Pathogenic

0.88

Eigen_PC

Pathogenic

0.83

FATHMM_MKL

Uncertain

0.95

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Uncertain

0.089

MetaRNN

Pathogenic

0.87

D;D;D

MetaSVM

Uncertain

0.19

MutationAssessor

Uncertain

2.9

M;.;M

MutationTaster

Benign

1.0

D;D;D

PrimateAI

Uncertain

0.68

PROVEAN

Uncertain

-3.7

D;.;D

REVEL

Uncertain

0.56

Sift

Uncertain

0.0040

D;.;D

Sift4G

Uncertain

0.026

D;D;D

Polyphen

1.0

D;.;D

Vest4

0.83

MVP

0.94

MPC

0.72

ClinPred

0.89

GERP RS

5.4

Varity_R

0.48

gMVP

0.62

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over