NM_003803.4:c.5041G>T

Variant names:

• chr18-3067279-C-A
• rs769553242
• NM_003803.4:c.5041G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_003803.4(MYOM1):​c.5041G>T​(p.Gly1681Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000689 in 1,451,620 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G1681D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MYOM1 NM_003803.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.256
• 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: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.094178826).

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOM1	NM_003803.4	MANE Select	c.5041G>T	p.Gly1681Cys	missense	Exon 38 of 38	NP_003794.3
	MYOM1	NM_019856.2		c.4753G>T	p.Gly1585Cys	missense	Exon 37 of 37	NP_062830.1	P52179-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYOM1	ENST00000356443.9	TSL:1 MANE Select	c.5041G>T	p.Gly1681Cys	missense	Exon 38 of 38	ENSP00000348821.4	P52179-1
	MYOM1	ENST00000261606.11	TSL:1	c.4753G>T	p.Gly1585Cys	missense	Exon 37 of 37	ENSP00000261606.7	P52179-2
	MYOM1	ENST00000941943.1		c.5005G>T	p.Gly1669Cys	missense	Exon 38 of 38	ENSP00000612002.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.89e-7 AC: 1 AN: 1451620 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 721174

⚠️ 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: 33226

American (AMR) AF: 0.00 AC: 0 AN: 43512

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25836

East Asian (EAS) AF: 0.00 AC: 0 AN: 39406

South Asian (SAS) AF: 0.0000118 AC: 1 AN: 84806

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52870

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4146

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1107858

Other (OTH) AF: 0.00 AC: 0 AN: 59960

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.32
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
CADD	Benign	13
DANN	Uncertain	0.97
DEOGEN2	Benign	0.044	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.18	N
LIST_S2	Benign	0.68	T
M_CAP	Benign	0.038	D
MetaRNN	Benign	0.094	T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	1.2	L
PhyloP100		-0.26
PrimateAI	Benign	0.25	T
PROVEAN	Benign	-1.5	N
REVEL	Benign	0.017
Sift	Benign	0.034	D
Sift4G	Uncertain	0.014	D
Polyphen		0.29	B
Vest4		0.20
MutPred		0.35		Gain of methylation at K1682 (P = 0.0168)
MVP		0.23
MPC		0.30
ClinPred		0.35	T
GERP RS		-1.6
Varity_R		0.10
gMVP		0.65
Mutation Taster		=98/2	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

Other links and lift over

dbSNP: rs769553242; hg19: chr18-3067277;