18-3067282-C-G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_003803.4(MYOM1):​c.5038G>C​(p.Gly1680Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000413 in 1,453,878 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign 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. G1680D) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

3
16

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 0.798

Publications

0 publications found
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 Gene-Disease associations (from GenCC):
  • hypertrophic cardiomyopathy
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.11203918).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MYOM1NM_003803.4 linkc.5038G>C p.Gly1680Arg missense_variant Exon 38 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.5038G>C p.Gly1680Arg missense_variant Exon 38 of 38 1 NM_003803.4 ENSP00000348821.4 P52179-1
MYOM1ENST00000261606.11 linkc.4750G>C p.Gly1584Arg missense_variant Exon 37 of 37 1 ENSP00000261606.7 P52179-2
MYOM1ENST00000581804.1 linkn.528G>C non_coding_transcript_exon_variant Exon 3 of 3 3

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD2 exomes
AF:
0.0000126
AC:
3
AN:
238160
AF XY:
0.0000232
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000413
AC:
6
AN:
1453878
Hom.:
0
Cov.:
33
AF XY:
0.00000692
AC XY:
5
AN XY:
722642
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33274
American (AMR)
AF:
0.0000456
AC:
2
AN:
43818
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25896
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39488
South Asian (SAS)
AF:
0.0000470
AC:
4
AN:
85088
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53016
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
4144
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1109138
Other (OTH)
AF:
0.00
AC:
0
AN:
60016
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.010105), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.392
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
33
ExAC
AF:
0.0000247
AC:
3

ClinVar

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

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1
Jul 07, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is present in population databases (rs762687220, gnomAD 0.01%). This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1680 of the MYOM1 protein (p.Gly1680Arg). This variant has not been reported in the literature in individuals affected with MYOM1-related conditions. 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. 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.38
BayesDel_addAF
Benign
-0.36
T
BayesDel_noAF
Benign
-0.55
CADD
Benign
18
DANN
Benign
0.96
DEOGEN2
Benign
0.037
T;.;.
Eigen
Benign
-0.31
Eigen_PC
Benign
-0.38
FATHMM_MKL
Benign
0.21
N
LIST_S2
Benign
0.82
T;T;T
M_CAP
Benign
0.028
D
MetaRNN
Benign
0.11
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.9
L;.;.
PhyloP100
0.80
PrimateAI
Benign
0.33
T
PROVEAN
Benign
-1.1
N;.;N
REVEL
Benign
0.059
Sift
Uncertain
0.015
D;.;D
Sift4G
Uncertain
0.034
D;T;D
Polyphen
0.77
P;.;D
Vest4
0.15
MutPred
0.33
Gain of MoRF binding (P = 0.0263);.;.;
MVP
0.57
MPC
0.22
ClinPred
0.45
T
GERP RS
4.2
Varity_R
0.072
gMVP
0.63
Mutation Taster
=89/11
polymorphism

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

Other links and lift over

dbSNP: rs762687220; hg19: chr18-3067280; API