rs397516105

chr14-23428978-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PP2 PP3_Strong

The NM_000257.4(MYH7):c.1384A>T(p.Ile462Phe) variant causes a missense change. The variant allele was found at a frequency of 0.0000266 in 1,614,094 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 Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. I462I) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000028 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:7
• Conservation: PhyloP100: 6.02

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_000257.4
• PP2: Missense variant where missense usually causes diseases, MYH7
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.951

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4	c.1384A>T	p.Ile462Phe	missense_variant	14/40	ENST00000355349.4
MYH7	NM_001407004.1	c.1384A>T	p.Ile462Phe	missense_variant	13/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4	c.1384A>T	p.Ile462Phe	missense_variant	14/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152200 Hom.: 0 Cov.: 32

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251488 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135918

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000280 AC: 41 AN: 1461894 Hom.: 0 Cov.: 33 AF XY: 0.0000248 AC XY: 18 AN XY: 727248

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: 0.0000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152200 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74354

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: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000756

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:3

Uncertain significance, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Jun 09, 2020	Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
Uncertain significance, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -

Cardiomyopathy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 23, 2023	This missense variant replaces isoleucine with phenylalanine at codon 462 of the MYH7 protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant is found within a highly conserved region of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MYH7-related disorders in the literature. This variant has been identified in 3/282886 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	All of Us Research Program, National Institutes of Health	Oct 02, 2023	This missense variant replaces isoleucine with phenylalanine at codon 462 of the MYH7 protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). This variant is found within a highly conserved region of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with MYH7-related disorders in the literature. This variant has been identified in 3/282886 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. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jan 23, 2013

Variant classified as Uncertain Significance - Favor Pathogenic. The Ile462Phe v ariant in MYH7 has not been reported in the literature nor previously identified by our laboratory. This variant has also not been identified in large and broad European American and African American populations by the NHLBI Exome Sequencin g Project (http://evs.gs.washington.edu/EVS), which increases the likelihood tha t the variant is pathogenic. However, we cannot exclude that it may be common in other populations. Isoleucine (Ile) at position 462 is highly conserved in mamm als and across evolutionarily distant species and the change to phenylalanine (P he) was predicted to be pathogenic using a computational tool clinically validat ed by our laboratory. This tool's pathogenic prediction is estimated to be corre ct 94% of the time (Jordan 2011). In addition, the vast majority of missense var iants in MYH7 are pathogenic (LMM unpublished data). In summary, although the lo w frequency and computational predictions all suggests that this variant is like ly to be pathogenic, additional studies are needed to fully assess the clinical significance of this variant. -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 27, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 462 of the MYH7 protein (p.Ile462Phe). This variant is present in population databases (rs397516105, gnomAD 0.004%). This variant has not been reported in the literature in individuals affected with MYH7-related conditions. ClinVar contains an entry for this variant (Variation ID: 42842). 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%. 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
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.42
Cadd	Pathogenic	29
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.2	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.71		Gain of catalytic residue at D461 (P = 0);
MVP		0.96
MPC		2.6
ClinPred		0.99	D
GERP RS		4.2
Varity_R		0.90
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: rs397516105; hg19: chr14-23898187;