18-3129452-C-G

Variant summary

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

The NM_003803.4(MYOM1):​c.2574G>C​(p.Arg858Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,676 control chromosomes in the GnomAD database, with no homozygous occurrence. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

2
17

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.58
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]

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 rank MANE Protein UniProt
MYOM1NM_003803.4 linkc.2574G>C p.Arg858Ser missense_variant Exon 18 of 38 ENST00000356443.9 NP_003794.3 P52179-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MYOM1ENST00000356443.9 linkc.2574G>C p.Arg858Ser missense_variant Exon 18 of 38 1 NM_003803.4 ENSP00000348821.4 P52179-1
MYOM1ENST00000261606.11 linkc.2506+1923G>C intron_variant Intron 17 of 36 1 ENSP00000261606.7 P52179-2
MYOM1ENST00000582016.1 linkn.130G>C non_coding_transcript_exon_variant Exon 1 of 3 4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000803
AC:
2
AN:
249184
Hom.:
0
AF XY:
0.00000740
AC XY:
1
AN XY:
135180
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000579
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461676
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727122
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000671
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1
Jun 27, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with serine, which is neutral and polar, at codon 858 of the MYOM1 protein (p.Arg858Ser). This variant is present in population databases (no rsID available, 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: 525010). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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
0.44
BayesDel_addAF
Benign
-0.24
T
BayesDel_noAF
Benign
-0.41
CADD
Benign
21
DANN
Benign
0.72
DEOGEN2
Benign
0.018
T
Eigen
Benign
-0.38
Eigen_PC
Benign
-0.18
FATHMM_MKL
Benign
0.68
D
LIST_S2
Benign
0.55
T
M_CAP
Benign
0.0071
T
MetaRNN
Uncertain
0.55
D
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.34
N
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-0.59
N
REVEL
Benign
0.099
Sift
Benign
0.59
T
Sift4G
Benign
0.27
T
Polyphen
0.049
B
Vest4
0.62
MutPred
0.49
Gain of glycosylation at R858 (P = 0.0019);
MVP
0.67
MPC
0.16
ClinPred
0.093
T
GERP RS
4.8
Varity_R
0.12
gMVP
0.42

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

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

Other links and lift over

dbSNP: rs1422382078; hg19: chr18-3129450; API