Genetic Variant MYOM1:p.Arg307His (chr18-3187489-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_003803.4(MYOM1):c.920G>A(p.Arg307His) variant causes a missense change. The variant allele was found at a frequency of 0.00000479 in 1,461,064 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

MYOM1
NM_003803.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

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 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
MYOM1	NM_003803.4 link	c.920G>A	p.Arg307His	missense_variant	Exon 5 of 38	ENST00000356443.9	NP_003794.3	P52179-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYOM1	ENST00000356443.9 link	c.920G>A	p.Arg307His	missense_variant	Exon 5 of 38	1	NM_003803.4	ENSP00000348821.4		P52179-1
MYOM1	ENST00000261606.11 link	c.920G>A	p.Arg307His	missense_variant	Exon 5 of 37	1		ENSP00000261606.7		P52179-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000803

AC:

AN:

248950

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135042

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000557

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000464

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461064

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726766

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.00000360

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 22, 2021

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R307H variant (also known as c.920G>A), located in coding exon 4 of the MYOM1 gene, results from a G to A substitution at nucleotide position 920. The arginine at codon 307 is replaced by histidine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Uncertain

0.038

BayesDel_noAF

Benign

-0.18

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.076

T;.;.

Eigen

Uncertain

0.51

Eigen_PC

Uncertain

0.49

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.93

D;D;D

M_CAP

Benign

0.082

MetaRNN

Uncertain

0.63

D;D;D

MetaSVM

Uncertain

-0.26

MutationAssessor

Benign

1.1

L;.;L

PrimateAI

Uncertain

0.63

PROVEAN

Uncertain

-2.4

N;.;N

REVEL

Uncertain

0.41

Sift

Uncertain

0.018

D;.;T

Sift4G

Benign

0.13

T;T;T

Polyphen

1.0

D;.;D

Vest4

0.47

MutPred

0.53

Loss of ubiquitination at K312 (P = 0.0909);.;Loss of ubiquitination at K312 (P = 0.0909);

MVP

0.90

MPC

0.45

ClinPred

0.89

GERP RS

4.5

Varity_R

0.26

gMVP

0.51

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