18-3214943-G-T

Position:

• chr18-3214943-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_003803.4(MYOM1):​c.281C>A​(p.Ser94Tyr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000692 in 1,445,002 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: MYOM1 NM_003803.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.58

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0443061).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYOM1	NM_003803.4	c.281C>A	p.Ser94Tyr	missense_variant	2/38	ENST00000356443.9	NP_003794.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYOM1	ENST00000356443.9	c.281C>A	p.Ser94Tyr	missense_variant	2/38	1	NM_003803.4	ENSP00000348821.4
MYOM1	ENST00000261606.11	c.281C>A	p.Ser94Tyr	missense_variant	2/37	1		ENSP00000261606.7
ENSG00000265399	ENST00000580139.1	n.198-2049G>T		intron_variant		2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.92e-7 AC: 1 AN: 1445002 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 716432

Gnomad4 AFR exome AF: 0.0000302

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.37
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.57
CADD	Benign	12
DANN	Benign	0.79
DEOGEN2	Benign	0.015	T;.
Eigen	Benign	-0.81
Eigen_PC	Benign	-0.57
FATHMM_MKL	Benign	0.026	N
LIST_S2	Benign	0.61	T;T
M_CAP	Benign	0.0038	T
MetaRNN	Benign	0.044	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-1.6	N;N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	0.57	N;N
REVEL	Benign	0.058
Sift	Benign	0.94	T;T
Sift4G	Benign	1.0	T;T
Polyphen		0.0	B;B
Vest4		0.13
MutPred		0.20		Loss of glycosylation at S94 (P = 0.0481);Loss of glycosylation at S94 (P = 0.0481);
MVP		0.24
MPC		0.31
ClinPred		0.036	T
GERP RS		4.0
Varity_R		0.029
gMVP		0.45

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

Publications

LitVar

Other links and lift over

dbSNP: rs761148558; hg19: chr18-3214941;