rs371855540

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM5PP2PP3

The NM_000257.4(MYH7):c.5459G>A(p.Arg1820Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,613,876 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1820W) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000016 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:7

Conservation

PhyloP100: 5.63

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]

MYH7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM5

Other missense variant is known to change same aminoacid residue: Variant chr14-23415096-G-A is described in ClinVar as [Uncertain_significance]. Clinvar id is 181282.Status of the report is reviewed_by_expert_panel, 3 stars. We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=4, Likely_pathogenic=2}.

PP2

Missense variant where missense usually causes diseases, MYH7

PP3

MetaRNN computational evidence supports a deleterious effect, 0.778

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4 linkuse as main transcript	c.5459G>A	p.Arg1820Gln	missense_variant	37/40	ENST00000355349.4
MYH7	NM_001407004.1 linkuse as main transcript	c.5459G>A	p.Arg1820Gln	missense_variant	36/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4 linkuse as main transcript	c.5459G>A	p.Arg1820Gln	missense_variant	37/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes

AF:

0.0000394

AC:

AN:

152248

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000735

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

251346

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135868

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000164

AC:

AN:

1461628

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

727148

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

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:

0.0000198

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000394

AC:

AN:

152248

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74376

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000735

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000567

Hom.:

Bravo

AF:

0.0000340

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:7

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	Jun 28, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Nov 30, 2023	This missense variant replaces arginine with glutamine at codon 1820 of the MYH7 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27282841). This variant has been identified in 5/251346 chromosomes in the general population by the Genome Aggregation Database (gnomAD). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Jun 14, 2023	This missense variant replaces arginine with glutamine at codon 1820 of the MYH7 protein. Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with hypertrophic cardiomyopathy (PMID: 27282841). This variant has been identified in 5/251346 chromosomes in the general population by the Genome Aggregation Database (gnomAD). 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. -

Hypertrophic cardiomyopathy

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jan 11, 2024

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1820 of the MYH7 protein (p.Arg1820Gln). This variant is present in population databases (rs371855540, gnomAD 0.006%). This missense change has been observed in individual(s) with distal myopathy (PMID: 27282841). This variant has been reported in individual(s) with autosomal dominant hypertrophic cardiomyopathy (Invitae); however, the role of the variant in this condition is currently unclear. ClinVar contains an entry for this variant (Variation ID: 419278). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MYH7 protein function with a positive predictive value of 95%. This variant disrupts the p.Arg1820 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 25666907). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 26, 2019

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Arg1820Gln variant in MYH7 has been reported in 1 individual with both hypertrophic cardiomyopathy and distal myopathy as well as in one sibling with only myopathy; however, both individuals as well as a third affected sibling had an additional pathogenic variant sufficient to cause distal myopathy, but which has not been previously associated with cardiomyopathy (Brand 2016). It has also been identified in 1 individual with HCM (LMM data) and has been identified in 5/251346 chromosomes by gnomAD (https://gnomad.broadinstitute.org). It has also been reported in ClinVar (Variation ID #419278). Computational prediction tools and conservation analysis suggest that the p.Arg1820Gln variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria Applied: PM2, PS4_Supporting, PP3. -

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 submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Sep 22, 2021

- -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Sep 12, 2018

The R1820Q variant of uncertain significance in the MYH7 gene has been previously reported in two sisters with distal myopathy, one of whom developed supraventricular tachycardia and HCM at the age of 64 years, however, it was absent from a third sibling with isolated distal myopathy (Brand et al., 2016). Brand et al. (2016) reported that all three siblings in this family also harbored a pathogenic missense variant in the TIA1 gene, which is associated with Welander distal myopathy, and this family had a paternal family history of cardiac disease but further segregation studies of the R1820Q variant were not reported. The R1820Q variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). Furthermore, R1820Q is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties, and this substitution occurs at a position that is conserved across species. Nevertheless, in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Additionally, although a missense variant at the same residue in the MYH7 gene (R1820W) has been reported in the Human Gene Mutation Database in association with myopathy (Stenson et al., 2014), the clinical significance of this variant also remains to be definitively determined. -

Cardiovascular phenotype

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 11, 2024

The p.R1820Q variant (also known as c.5459G>A), located in coding exon 35 of the MYH7 gene, results from a G to A substitution at nucleotide position 5459. The arginine at codon 1820 is replaced by glutamine, an amino acid with highly similar properties. This alteration was detected in two of three siblings in a family, all of whom also carried the TIA1 p.E384K alteration. Phenotypes of the two siblings with both alterations included progressive asymmetric distal limb weakness, mild distal myopathy, supraventricular tachycardia and hypertrophic cardiomyopathy. The third sibling who only carried the TIA1 alteration had isolated distal myopathy (Brand P et al. Neuromuscul. Disord., 2016 08;26:511-5). This variant has also been reported in an individual with arrhythmogenic right ventricular cardiomyopathy (ARVC) and co-occurring DSG2 variants, as well as in an exome cohort with limited clinical details (Homburger JR et al. Proc Natl Acad Sci U S A, 2016 06;113:6701-6; Lin Y et al. J Electrocardiol Jun;51:837-843). This alteration also been reported in association with transposition of the great arteries (Blue GM et al. Am Heart J, 2022 Feb;244:1-13). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.16

CardioboostCm

Uncertain

0.49

BayesDel_addAF

Uncertain

0.059

BayesDel_noAF

Uncertain

0.020

Cadd

Pathogenic

Dann

Pathogenic

1.0

DEOGEN2

Pathogenic

0.82

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.71

FATHMM_MKL

Uncertain

0.93

LIST_S2

Uncertain

0.88

M_CAP

Pathogenic

0.88

MetaRNN

Pathogenic

0.78

MetaSVM

Uncertain

0.53

MutationAssessor

Pathogenic

3.4

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.69

PROVEAN

Benign

-2.3

REVEL

Pathogenic

0.66

Sift

Uncertain

0.0010

Sift4G

Benign

0.14

Polyphen

0.96

Vest4

0.47

MVP

0.93

MPC

1.4

ClinPred

0.77

GERP RS

5.3

Varity_R

0.61

gMVP

0.85

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

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

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over