rs121913641

Positions:

• chr14-23425970-C-G
• chr14-23425970-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.2156G>C​(p.Arg719Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R719Q) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 0.861

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]

ACMG classification

Verdict is Pathogenic. Variant got 19 ACMG points.

• PM1: In a helix (size 7) in uniprot entity MYH7_HUMAN there are 12 pathogenic changes around while only 0 benign (100%) in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23425970-C-T is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH7. . Gene score misZ 3.9329 (greater than the threshold 3.09). Trascript score misZ 6.7889 (greater than threshold 3.09). GenCC has associacion of gene with hyaline body myopathy, MYH7-related skeletal myopathy, dilated cardiomyopathy 1S, congenital myopathy 7A, myosin storage, autosomal dominant, dilated cardiomyopathy, left ventricular noncompaction, myopathy, myosin storage, autosomal dominant, hypertrophic cardiomyopathy, congenital heart disease, Ebstein anomaly, arrhythmogenic right ventricular cardiomyopathy, myopathy, myosin storage, autosomal recessive, hypertrophic cardiomyopathy 1, familial isolated dilated cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.963
• PP5: Variant 14-23425970-C-G is Pathogenic according to our data. Variant chr14-23425970-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 217460.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-23425970-C-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.2156G>C	p.Arg719Pro	missense_variant	19/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.2156G>C	p.Arg719Pro	missense_variant	18/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.2156G>C	p.Arg719Pro	missense_variant	19/40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 24, 2019

This variant has been observed in several individuals with clinical features of hypertrophic cardiomyopathy (PMID: 25935763). ClinVar contains an entry for this variant (Variation ID: 217460). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with proline at codon 719 of the MYH7 protein (p.Arg719Pro). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and proline. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65"). This variant is found within a region of MYH7 between codons 181 and 937 that contains the majority of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). 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. This variant disrupts the p.Arg719 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7848441, 23140321). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. -

Hypertrophic cardiomyopathy 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory of Genetics and Molecular Cardiology, University of São Paulo

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- -

not specified Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Jun 10, 2015

Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. Arg719Pro (R719P; G>C at nucleotide level) Other changes at this same codon, Arg719Trp and Arg719Gln, have been associated with HCM (Harvard Sarcomere Protein Gene Mutation Database). Variation at nearby loci of MYH7 (within 10 amino acids to either side) has been associated with disease, supporting the functional importance of this region of the protein. These HCM variants include Arg712Leu, Gly716Arg, Arg723Cys, Arg723Gly, and Ala728Val (Harvard Sarcomere Protein Gene Mutation Database). This is a nonconservative amino acid change from a basic, positively-charged Arginine to a nonpolar Proline. The Arginine at codon 719 is highly conserved across 41 vertebrate species examined (it is a Lysine in 7 species: Chicken, Tetraodon, Fugu, Stickleback, Medaka, Zebrafish, and Lamprey). Surrounding residues are also highly conserved. In silico analysis with PolyPhen-2 (http://genetics.bwh.harvard.edu/pph2/) predicts the variant to be “possibly damaging”. In total the variant has not been seen in ~5300 individuals from publicly available population datasets. There is no variation at codon 719 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~3500 Caucasian and ~1800 African American individuals (as of 1/15/2012). There is also no variation at this codon listed in dbSNP or 1000 genomes (as of 1/15/2012). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Benign	0.72	D
LIST_S2	Benign	0.83	T
M_CAP	Pathogenic	0.90	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	0.93	D
MutationAssessor	Benign	2.0	M
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-3.9	D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.053	T
Polyphen		0.89	P
Vest4		0.90
MutPred		0.78		Loss of MoRF binding (P = 8e-04);
MVP		0.99
MPC		1.6
ClinPred		0.99	D
GERP RS		5.0
Varity_R		0.96
gMVP		1.0

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: rs121913641; hg19: chr14-23895179;