rs730880852

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1PM2

The NM_000257.4(MYH7):​c.745C>T​(p.Arg249Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,874 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. R249R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MYH7
NM_000257.4 stop_gained

Scores

2
2
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:4

Conservation

PhyloP100: 1.33
Variant links:
Genes affected
MYH7 (HGNC:7577): (myosin heavy chain 7) Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing distal myopathy. [provided by RefSeq, May 2022]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MYH7NM_000257.4 linkuse as main transcriptc.745C>T p.Arg249Ter stop_gained 9/40 ENST00000355349.4
MYH7NM_001407004.1 linkuse as main transcriptc.745C>T p.Arg249Ter stop_gained 8/39

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MYH7ENST00000355349.4 linkuse as main transcriptc.745C>T p.Arg249Ter stop_gained 9/401 NM_000257.4 P1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251458
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135902
show subpopulations
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461874
Hom.:
0
Cov.:
33
AF XY:
0.00
AC XY:
0
AN XY:
727236
show subpopulations
Gnomad4 AFR exome
AF:
0.00
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:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.0000329
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:4
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Cardiomyopathy Pathogenic:1Uncertain:2
Uncertain significance, criteria provided, single submitterclinical testingAll of Us Research Program, National Institutes of HealthJul 19, 2023This variant changes 1 nucleotide in exon 9 of the MYH7 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in an individual affected with left ventricular non-compaction (PMID: 28798025). This variant has been identified in 1/251458 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Clinical relevance of loss-of-function MYH7 truncation variants in autosomal dominant cardiovascular disorders is not clearly established. The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Likely pathogenic, criteria provided, single submitterclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineFeb 08, 2019The p.Arg249X variant in MYH7 has been reported in one individual with left ventricular non-compaction (Miszalski-Jamka 2017). It has also been identified in 1/113734 European chromosomes by gnomAD (http://gnomad.broadinstitute.org) and has been reported in ClinVar (Variation ID 407183). This nonsense variant leads to a premature termination codon at position 249, which is predicted to lead to a truncated or absent protein. Although heterozygous loss-of-function (LOF) variants in MYH7 are not believed to be pathogenic for autosomal dominant forms of cardiomyopathy, there is evidence that can they lead to severe and early onset disease when present in trans with a second MYH7 variant (LMM data). In summary, although additional studies are required to fully establish its clinical significance, the p.Arg249X variant is likely pathogenic for cardiomyopathy in an autosomal recessive manner. ACMG/AMP Criteria applied: PVS1, PM2. -
Uncertain significance, criteria provided, single submitterclinical testingColor Diagnostics, LLC DBA Color HealthJul 06, 2023This variant changes 1 nucleotide in exon 9 of the MYH7 gene, creating a premature translation stop signal. This variant is expected to result in an absent or non-functional protein product. This variant has been reported in an individual affected with left ventricular non-compaction (PMID: 28798025). This variant has been identified in 1/251458 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Clinical relevance of loss-of-function MYH7 truncation variants in autosomal dominant cardiovascular disorders is not clearly established. The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Congenital myopathy with fiber type disproportion;C1834481:Dilated cardiomyopathy 1S;C1842160:Myosin storage myopathy;C1850709:Myopathy, myosin storage, autosomal recessive;C3495498:Hypertrophic cardiomyopathy 1;C4552004:MYH7-related skeletal myopathy Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingFulgent Genetics, Fulgent GeneticsNov 05, 2021- -
Hypertrophic cardiomyopathy Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingInvitaeAug 27, 2021This sequence change creates a premature translational stop signal (p.Arg249*) in the MYH7 gene. It is expected to result in an absent or disrupted protein product. However, the current clinical and genetic evidence is not sufficient to establish whether loss-of-function variants in MYH7 cause disease. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with MYH7-related conditions. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
37
DANN
Uncertain
0.99
Eigen
Benign
0.15
Eigen_PC
Benign
-0.077
FATHMM_MKL
Uncertain
0.89
D
MutationTaster
Benign
1.0
A
Vest4
0.92
GERP RS
2.6

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs730880852; hg19: chr14-23900678; COSMIC: COSV62517904; API