NM_003803.4:c.2697A>G

Variant names:

• chr18-3129329-T-C
• rs771666952
• NM_003803.4:c.2697A>G

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BP7 BS2

The NM_003803.4(MYOM1):​c.2697A>G​(p.Val899Val) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,712 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. V899V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: MYOM1 NM_003803.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.753
• 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 -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.54).
• BP7: Synonymous conserved (PhyloP=0.753 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 6 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.2697A>G	p.Val899Val	synonymous	Exon 18 of 38	NP_003794.3
	MYOM1	NM_019856.2		c.2506+2046A>G		intron	N/A	NP_062830.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOM1	ENST00000356443.9	TSL:1 MANE Select	c.2697A>G	p.Val899Val	synonymous	Exon 18 of 38	ENSP00000348821.4
	MYOM1	ENST00000261606.11	TSL:1	c.2506+2046A>G		intron	N/A	ENSP00000261606.7
	MYOM1	ENST00000582016.1	TSL:4	n.253A>G		non_coding_transcript_exon	Exon 1 of 3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000802 AC: 2 AN: 249264 AF XY: 0.0000148

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: 0.000165

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461712 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727138

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.000173 AC: 1 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111870

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.54
CADD	Benign	12
DANN	Benign	0.77
PhyloP100		0.75

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs771666952; hg19: chr18-3129327;