18-3164324-C-G

Variant names:

• chr18-3164324-C-G
• rs193006519
• NM_003803.4:c.1455G>C

Variant summary

Our verdict is Benign. The variant received -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_003803.4(MYOM1):​c.1455G>C​(p.Arg485Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000573 in 1,613,090 control chromosomes in the GnomAD database, including 4 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0030 (2 hom., cov: 33)
  • Exomes 𝑓: 0.00032 (2 hom.)
• Consequence: MYOM1 NM_003803.4 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:3
• Conservation: PhyloP100: 1.03
• Publications: 2 publications found

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

ACMG classification

Our verdict: Benign. The variant received -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BP6: Variant 18-3164324-C-G is Benign according to our data. Variant chr18-3164324-C-G is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 226802.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=1.03 with no splicing effect.
• BS2: High AC in GnomAd4 at 454 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_003803.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOM1	NM_003803.4	MANE Select	c.1455G>C	p.Arg485Arg	synonymous	Exon 10 of 38	NP_003794.3
	MYOM1	NM_019856.2		c.1455G>C	p.Arg485Arg	synonymous	Exon 10 of 37	NP_062830.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOM1	ENST00000356443.9	TSL:1 MANE Select	c.1455G>C	p.Arg485Arg	synonymous	Exon 10 of 38	ENSP00000348821.4
	MYOM1	ENST00000261606.11	TSL:1	c.1455G>C	p.Arg485Arg	synonymous	Exon 10 of 37	ENSP00000261606.7

Frequencies

GnomAD3 genomes AF: 0.00298 AC: 453 AN: 152246 Hom.: 2 Cov.: 33

Gnomad AFR AF: 0.0102

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00137

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: 0.00335

GnomAD2 exomes AF: 0.000794 AC: 196 AN: 246974 AF XY: 0.000500

Gnomad AFR exome AF: 0.0109

Gnomad AMR exome AF: 0.000700

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000357

Gnomad OTH exome AF: 0.000333

GnomAD4 exome AF: 0.000322 AC: 471 AN: 1460726 Hom.: 2 Cov.: 30 AF XY: 0.000253 AC XY: 184 AN XY: 726498

African (AFR) AF: 0.0110 AC: 368 AN: 33472

American (AMR) AF: 0.000784 AC: 35 AN: 44620

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26076

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 85964

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53364

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.0000270 AC: 30 AN: 1111420

Other (OTH) AF: 0.000630 AC: 38 AN: 60352

GnomAD4 genome AF: 0.00298 AC: 454 AN: 152364 Hom.: 2 Cov.: 33 AF XY: 0.00272 AC XY: 203 AN XY: 74516

African (AFR) AF: 0.0102 AC: 425 AN: 41588

American (AMR) AF: 0.00137 AC: 21 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68036

Other (OTH) AF: 0.00331 AC: 7 AN: 2114

Alfa AF: 0.000268 Hom.: 0

Bravo AF: 0.00366

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

May 17, 2022

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity.

Nov 24, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Arg485Arg in exon 10 of MYOM1: This variant is not expected to have clinical sig nificance because it does not alter an amino acid residue and is not located wit hin the splice consensus sequence. It has been identified in 0.8% (32/3976) of A frican American chromosomes from a broad population by the NHLBI Exome Sequencin g Project (http://evs.gs.washington.edu/EVS; dbSNP rs193006519).

Hypertrophic cardiomyopathy Benign:1

Jan 16, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	6.1
DANN	Benign	0.56
PhyloP100		1.0
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs193006519; hg19: chr18-3164322;