chr18-3116356-G-A

Position:

chr18-3116356-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_003803.4(MYOM1):c.3278C>T(p.Ala1093Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000267 in 1,611,896 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000046 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000025 ( 1 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 4.66

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 0 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.15857041).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYOM1	NM_003803.4 linkuse as main transcript	c.3278C>T	p.Ala1093Val	missense_variant	21/38	ENST00000356443.9	NP_003794.3	P52179-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYOM1	ENST00000356443.9 linkuse as main transcript	c.3278C>T	p.Ala1093Val	missense_variant	21/38	1	NM_003803.4	ENSP00000348821.4		P52179-1
MYOM1	ENST00000261606.11 linkuse as main transcript	c.2990C>T	p.Ala997Val	missense_variant	20/37	1		ENSP00000261606.7		P52179-2

Frequencies

GnomAD3 genomes

AF:

0.0000460

AC:

AN:

152150

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000242

AC:

AN:

247674

Hom.:

AF XY:

0.0000223

AC XY:

AN XY:

134418

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.0000329

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000357

Gnomad OTH exome

AF:

0.000166

GnomAD4 exome

AF:

0.0000247

AC:

AN:

1459746

Hom.:

Cov.:

AF XY:

0.0000234

AC XY:

AN XY:

726114

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000288

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000460

AC:

AN:

152150

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74332

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000453

ExAC

AF:

0.0000331

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

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	Jan 23, 2024	The c.3278C>T (p.A1093V) alteration is located in exon 21 (coding exon 20) of the MYOM1 gene. This alteration results from a C to T substitution at nucleotide position 3278, causing the alanine (A) at amino acid position 1093 to be replaced by a valine (V). Based on insufficient or conflicting evidence, 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	Nov 12, 2015	The p.Ala1093Val variant in MYOM1 has not been previously reported in individual s with cardiomyopathy, but has been identified in 3/58954 European chromosomes b y the Exome Aggregation Consortium (ExAC, http://exac.broadinstitute.org; dbSNP rs749676865). Alanine (Ala) at position 1093 is not conserved in mammals or evol utionarily distant species and 2 mammals (black flying fox, megabat) carry a val ine (Val) at this position, raising the possibility that this change may be tole rated. In summary, the clinical significance of the p.Ala1093Val variant is unce rtain. -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 09, 2022

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 1093 of the MYOM1 protein (p.Ala1093Val). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 229021). This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. This variant is present in population databases (rs749676865, gnomAD 0.004%). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.27

BayesDel_addAF

Benign

-0.27

BayesDel_noAF

Benign

-0.50

CADD

Benign

DANN

Uncertain

0.98

DEOGEN2

Benign

0.044

T;.;.

Eigen

Benign

-0.51

Eigen_PC

Benign

-0.44

FATHMM_MKL

Uncertain

0.82

LIST_S2

Benign

0.76

T;T;T

M_CAP

Benign

0.017

MetaRNN

Benign

0.16

T;T;T

MetaSVM

Benign

-1.0

MutationAssessor

Benign

-0.050

N;.;.

PrimateAI

Benign

0.35

PROVEAN

Benign

-1.5

N;.;N

REVEL

Benign

0.16

Sift

Benign

0.24

T;.;T

Sift4G

Benign

0.15

T;T;T

Polyphen

0.71

P;.;B

Vest4

0.24

MVP

0.75

MPC

0.14

ClinPred

0.24

GERP RS

2.0

Varity_R

0.047

gMVP

0.21

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