18-3164326-G-A

Position:

chr18-3164326-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_003803.4(MYOM1):c.1453C>T(p.Arg485Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,612,724 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.35

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 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYOM1	NM_003803.4 linkuse as main transcript	c.1453C>T	p.Arg485Trp	missense_variant	10/38	ENST00000356443.9	NP_003794.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYOM1	ENST00000356443.9 linkuse as main transcript	c.1453C>T	p.Arg485Trp	missense_variant	10/38	1	NM_003803.4	ENSP00000348821	P2	P52179-1
MYOM1	ENST00000261606.11 linkuse as main transcript	c.1453C>T	p.Arg485Trp	missense_variant	10/37	1		ENSP00000261606	A2	P52179-2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152178

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.0000243

AC:

AN:

246672

Hom.:

AF XY:

0.0000224

AC XY:

AN XY:

133736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000561

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000447

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000219

AC:

AN:

1460546

Hom.:

Cov.:

AF XY:

0.0000248

AC XY:

AN XY:

726372

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000101

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000243

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152178

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74342

show subpopulations

Gnomad4 AFR

AF:

0.0000483

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:

0.0000434

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000248

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

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

Jan 30, 2024

The c.1453C>T (p.R485W) alteration is located in exon 10 (coding exon 9) of the MYOM1 gene. This alteration results from a C to T substitution at nucleotide position 1453, causing the arginine (R) at amino acid position 485 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 11, 2023

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 485 of the MYOM1 protein (p.Arg485Trp). This variant is present in population databases (rs776661300, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. ClinVar contains an entry for this variant (Variation ID: 567886). 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 with a negative predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.48

BayesDel_addAF

Benign

-0.17

BayesDel_noAF

Benign

-0.32

CADD

Uncertain

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.060

T;.;.

Eigen

Uncertain

0.25

Eigen_PC

Uncertain

0.25

FATHMM_MKL

Benign

0.69

LIST_S2

Uncertain

0.94

D;D;D

M_CAP

Benign

0.043

MetaRNN

Uncertain

0.55

D;D;D

MetaSVM

Benign

-0.78

MutationAssessor

Benign

0.20

N;.;N

MutationTaster

Benign

1.0

N;N;N

PrimateAI

Benign

0.48

PROVEAN

Benign

-1.4

N;.;N

REVEL

Uncertain

0.33

Sift

Uncertain

0.020

D;.;T

Sift4G

Benign

0.19

T;T;T

Polyphen

1.0

D;.;D

Vest4

0.51

MutPred

0.62

Loss of catalytic residue at R485 (P = 0.0924);.;Loss of catalytic residue at R485 (P = 0.0924);

MVP

0.91

MPC

0.54

ClinPred

0.42

GERP RS

4.9

Varity_R

0.13

gMVP

0.53

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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