chr18-3116445-G-C

Variant names:

• chr18-3116445-G-C
• rs1060504727
• NM_003803.4:c.3189C>G

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.3189C>G​(p.Val1063Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,460,308 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: MYOM1 NM_003803.4 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: 0.471
• Publications: 0 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=-0.83).
• BP6: Variant 18-3116445-G-C is Benign according to our data. Variant chr18-3116445-G-C is described in ClinVar as Likely_benign. ClinVar VariationId is 416042.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.471 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 7 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.3189C>G	p.Val1063Val	synonymous	Exon 21 of 38	NP_003794.3
	MYOM1	NM_019856.2		c.2901C>G	p.Val967Val	synonymous	Exon 20 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.3189C>G	p.Val1063Val	synonymous	Exon 21 of 38	ENSP00000348821.4
	MYOM1	ENST00000261606.11	TSL:1	c.2901C>G	p.Val967Val	synonymous	Exon 20 of 37	ENSP00000261606.7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000810 AC: 2 AN: 246922 AF XY: 0.00000745

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: 0.0000179

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1460308 Hom.: 0 Cov.: 30 AF XY: 0.00000275 AC XY: 2 AN XY: 726354

African (AFR) AF: 0.00 AC: 0 AN: 33458

American (AMR) AF: 0.00 AC: 0 AN: 44620

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86100

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53084

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 0.00000450 AC: 5 AN: 1111260

Other (OTH) AF: 0.00 AC: 0 AN: 60232

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000546

EpiControl AF: 0.00

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:1

Jun 17, 2025

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.

Hypertrophic cardiomyopathy Benign:1

Nov 14, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely 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	-0.83
CADD	Benign	0.49
DANN	Benign	0.49
PhyloP100		0.47

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

Other links and lift over

dbSNP: rs1060504727; hg19: chr18-3116443;