18-3134651-G-C

Position:

chr18-3134651-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2BP4

The NM_003803.4(MYOM1):c.2383C>G(p.Arg795Gly) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000913 in 1,610,404 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000099 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense, splice_region

Scores

Splicing: ADA: 0.1264

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 3.07

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 1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.35205883).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYOM1	NM_003803.4 linkuse as main transcript	c.2383C>G	p.Arg795Gly	missense_variant, splice_region_variant	16/38	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.2383C>G	p.Arg795Gly	missense_variant, splice_region_variant	16/38	1	NM_003803.4	ENSP00000348821	P2	P52179-1
MYOM1	ENST00000261606.11 linkuse as main transcript	c.2383C>G	p.Arg795Gly	missense_variant, splice_region_variant	16/37	1		ENSP00000261606	A2	P52179-2

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

152084

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000283

AC:

AN:

247460

Hom.:

AF XY:

0.0000373

AC XY:

AN XY:

134212

show subpopulations

Gnomad AFR exome

AF:

0.0000647

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000536

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000994

AC:

145

AN:

1458320

Hom.:

Cov.:

AF XY:

0.000105

AC XY:

AN XY:

724902

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

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:

0.000127

Gnomad4 OTH exome

AF:

0.0000498

GnomAD4 genome

AF:

0.0000132

AC:

AN:

152084

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74258

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000491

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.00000827

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Feb 25, 2024	The p.R795G variant (also known as c.2383C>G), located in coding exon 15 of the MYOM1 gene, results from a C to G substitution at nucleotide position 2383. The arginine at codon 795 is replaced by glycine, an amino acid with 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Aug 06, 2015	The p.Arg795Gly variant in MYOM1 has not been previously reported in individuals with cardiomyopathy, but has been identified in 1/65584 European chromosomes by the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP r s201618512). Computational prediction tools and conservation analysis suggest th at the p.Arg795Gly variant may impact the protein, though this information is no t predictive enough to determine pathogenicity. This variant is located in the l ast three bases of the exon, which is part of the 3' splice region. Computationa l tools do not suggest an impact to splicing. However, this information is not p redictive enough to rule out pathogenicity. In summary, the clinical significan ce of the p.Arg795Gly variant is uncertain. -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 17, 2022

This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. This variant is present in population databases (rs201618512, gnomAD 0.007%). This sequence change replaces arginine, which is basic and polar, with glycine, which is neutral and non-polar, at codon 795 of the MYOM1 protein (p.Arg795Gly). ClinVar contains an entry for this variant (Variation ID: 229019). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.53

BayesDel_addAF

Pathogenic

0.32

BayesDel_noAF

Pathogenic

0.19

CADD

Uncertain

DANN

Uncertain

1.0

Eigen

Uncertain

0.42

Eigen_PC

Uncertain

0.36

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.71

M_CAP

Benign

0.034

MetaRNN

Benign

0.35

MutationTaster

Benign

1.0

D;D;D

Sift4G

Uncertain

0.026

Vest4

0.26

MVP

0.85

ClinPred

0.96

GERP RS

2.4

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.13

dbscSNV1_RF

Benign

0.31

SpliceAI score (max)

0.35

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.35

Position offset: -1

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