NM_000257.4:c.452C>T

Variant names:

• chr14-23432689-G-A
• rs730880837
• NM_000257.4:c.452C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000257.4(MYH7):​c.452C>T​(p.Pro151Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,844 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/23 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P151S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:1 U:8
• Conservation: PhyloP100: 9.75
• Publications: 1 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1S

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• MYH7-related skeletal myopathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• myopathy, myosin storage, autosomal recessive

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• myopathy, myosin storage, autosomal dominant

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• congenital myopathy 7A, myosin storage, autosomal dominant

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ebstein anomaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hyaline body myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• left ventricular noncompaction

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• congenital heart disease

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 23 uncertain in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the MYH7 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 341 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 3.9329 (above the threshold of 3.09). Trascript score misZ: 6.7889 (above the threshold of 3.09). GenCC associations: The gene is linked to myopathy, myosin storage, autosomal recessive, MYH7-related skeletal myopathy, congenital myopathy 7A, myosin storage, autosomal dominant, Ebstein anomaly, hyaline body myopathy, left ventricular noncompaction, hypertrophic cardiomyopathy 1, dilated cardiomyopathy 1S, dilated cardiomyopathy, congenital heart disease, familial isolated dilated cardiomyopathy, myopathy, myosin storage, autosomal dominant, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.979

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.452C>T	p.Pro151Leu	missense_variant	Exon 5 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.452C>T	p.Pro151Leu	missense_variant	Exon 4 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.452C>T	p.Pro151Leu	missense_variant	Exon 5 of 40	1	NM_000257.4	ENSP00000347507.3
MYH7	ENST00000713768.1	c.452C>T	p.Pro151Leu	missense_variant	Exon 5 of 41			ENSP00000519070.1
MYH7	ENST00000713769.1	c.452C>T	p.Pro151Leu	missense_variant	Exon 4 of 39			ENSP00000519071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461844 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727222

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112010

Other (OTH) AF: 0.0000166 AC: 1 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:2

Jan 29, 2015

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Pro151Leu variant in MYH7 has not been previously reported in individuals with cardiomyop athy and was absent from large population studies. Proline (Pro) at position 151 is highly conserved in evolution and the change to leucine (Leu) was predicted to be pathogenic using a computational tool clinically validated by our laborato ry. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). In summary, the clinical significance of the p.Pro151Leu variant is uncertain but there is some suspicion for a pathogenic role. -

May 13, 2014

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

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. p.Pro151Leu (c.452C>T) in the MYH7 gene. The vairant is novel. This is a semi conservative amino acid substitution with a non polar Proline replaced with a non polar Leucine. In silico analysis predicts the amino acid change to be probably damaging. The Proline at codon 151 is conserved across species. Variants in nearby codons (p. Lys146Asn, p.Ser148Ile) have been reported in association with HCM (Stenson P et al 2003). I could not find other variants at codon 151 reported in association with disease. There is no variation at codon 151 currently listed in the NHLBI Exome Sequencing Project dataset, which includes variant calls on ~6500 Caucasian and African American individuals (as of Aug 12th 2012). -

not provided Uncertain:2

May 04, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Located in the myosin motor domain, a region enriched with missense variants reported in association with HCM (Walsh et al., 2017; Kelly et al., 2018); Reported in association of LVNC in published literatutre ( (PMIDs 33500567; 27854218); This variant is associated with the following publications: (PMID: 27854218, 27532257, 29300372, 33500567) -

Oct 08, 2020

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Congenital myopathy Pathogenic:1

Dec 01, 2015

Center for Genetic Medicine Research, Children's National Medical Center

Significance: Likely pathogenic

Review Status: flagged submission

Collection Method: research

- -

Cardiomyopathy Uncertain:1

Nov 09, 2020

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

See cases Uncertain:1

Nov 17, 2020

Petrovsky National Research Centre of Surgery, The Federal Agency for Scientific Organizations

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

We observed the c.452C>T (p.P151L) genetic variant in a 22-y.o. proband diagnosed with left ventricular non-compaction and heart rhythm disorders. To our knowledge, the p.P151L variant was absent in large population studies. According to the online in silico analysis (PolyPhen2, SIFT, MutationTaster), the p.P151L variant is probably pathogenic. In the absence of family screening and functional studies we can only classify the p.P151L genetic variant as the variant on uncertain clinical significance. -

Hypertrophic cardiomyopathy Uncertain:1

Apr 13, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. ClinVar contains an entry for this variant (Variation ID: 181305). This missense change has been observed in individual(s) with congenital myopathy and/or left ventricular noncompaction (PMID: 27854218, 33500567). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 151 of the MYH7 protein (p.Pro151Leu). 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. -

Cardiovascular phenotype Uncertain:1

Jun 11, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P151L variant (also known as c.452C>T), located in coding exon 3 of the MYH7 gene, results from a C to T substitution at nucleotide position 452. The proline at codon 151 is replaced by leucine, an amino acid with similar properties. This alteration was identified in an individual with congenital myopathy; however additional information was not provided (Punetha J et al. J Neuromuscul Dis, 2016 05;3:209-225). This alteration has also been reported in a left ventricular non-compaction (LVNC) cohort (Mazzarotto F et al. Genet Med, 2021 May;23:856-864). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.94
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.93	D
Eigen	Uncertain	0.68
Eigen_PC	Uncertain	0.44
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		9.7
PrimateAI	Pathogenic	0.80	D
PROVEAN	Pathogenic	-7.7	D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.012	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.77		Loss of disorder (P = 0.0132);
MVP		0.99
MPC		2.2
ClinPred		1.0	D
GERP RS		2.5
Varity_R		0.86
gMVP		0.95
Mutation Taster		=16/84	disease causing (ClinVar)

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: rs730880837; hg19: chr14-23901898;