14-23418220-C-T

Position:

• chr14-23418220-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000257.4(MYH7):​c.4159G>A​(p.Glu1387Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,100 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 (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts P:2 U:11
• Conservation: PhyloP100: 7.62

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 9 ACMG points.

• PM1: In a helix (size 64) in uniprot entity MYH7_HUMAN there are 16 pathogenic changes around while only 1 benign (94%) in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• 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, 0.964

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.4159G>A	p.Glu1387Lys	missense_variant	30/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.4159G>A	p.Glu1387Lys	missense_variant	29/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.4159G>A	p.Glu1387Lys	missense_variant	30/40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251448 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135908

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: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461100 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726858

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: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:2 Uncertain:11

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Oct 17, 2023	Identified in a family with HCM who also harbored c.(A934V) in cis (Wang et al., 2019); 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; This variant is associated with the following publications: (PMID: 28687478, 27247418, 21310275, 29121657, 34542152, 31638223) -
Likely pathogenic, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Likely pathogenic, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, University Medical Center Utrecht	-	- -

Hypertrophic cardiomyopathy 1 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute	May 03, 2019	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Apr 27, 2017	This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen	Jun 25, 2024	Detected in the compound-heterozygous state together with MYH7:ENST00000355349.4:c.4943del:p.Ser1648ThrfsTer3 in a 6 weeks old deceased infant suspected to suffer sudden cardiac death and showing cardiomegaly upon autopsy. -

not specified Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Jul 07, 2014

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.Glu1387Lys (c.4159 G>A) in the MYH7 gene. The variant has been seen in at least one unrelated cases of HCM (not including this patient's family). No segregation data is available. GeneDx notes the variant is novel, however I found a report of the variant in a poster from the 2010 European Society of Cardiology meeting (Waldmuller et al 2010, Http://spo.escardio.org/eslides/view.aspx?eevtid=40&fp=P2062). I could not find a report of this variant in any publications by the same group. In the poster they report observing the variant in one of 20 patents with "suspected familial HCM" who underwent sequencing of 17 cardiomyopathy associated genes. Ancestry is not noted, however the report is by a German group. No segregation data was reported. The same group also reported on the variant, very likely from the same case, at the 2010 Congress of the German Human Genetics Society (Waldmuller et al 2010). It is not in ClinVar. In silico analysis with PolyPhen-2 predicts the variant to be probably damaging (HumVar score 0.999). The glutamic acid at codon 1387 is completely conserved across species, as are neighboring amino acids. I could not find any other variants reported in association with disease at this codon, however there are variants reported in association with cardiomyopathy at nearby codons (p.Ala1379Thr (per the Seidman's database), p.Arg1382Gln, p.Arg1382Trp (per GeneDx report, referencing HGMD)). In total the variant has not been seen in ~6500 individuals from publicly available population datasets. There is no variation at codon 1387 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~6500 Caucasian and African American individuals (as of July 23rd 2014).There is also no variation at this codon listed in dbSNP (as of July 24th, 2014). -

Dilated cardiomyopathy 1S Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

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

Apr 28, 2023

- -

MYH7-related skeletal myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Myosin storage myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 27, 2017

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 24, 2023

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. 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: 181244). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy or dilated cardiomyopathy (PMID: 27247418, 29121657, 31638223). This variant is present in population databases (rs730880792, gnomAD 0.003%). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 1387 of the MYH7 protein (p.Glu1387Lys). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 20, 2024

The p.E1387K variant (also known as c.4159G>A), located in coding exon 28 of the MYH7 gene, results from a G to A substitution at nucleotide position 4159. The glutamic acid at codon 1387 is replaced by lysine, an amino acid with similar properties. This aleratation has been detected in hypertrophic cardiomyopathy (HCM) cohorts; however, details were limited (Homburger JR et al. Proc. Natl. Acad. Sci. U.S.A., 2016 06;113:6701-6; Viswanathan SK et al. PLoS One. 2017 Nov;12(11):e0187948). This variant co-occurred with a second MYH7 variant in a family with HCM (Wang B et al. Mol Med Rep. 2019 Dec;20(6):5229-5238). Another alteration affecting the same amino acid (p.E1387Q, c.4159G>C) has also been reported in association with HCM (O'Mahony C et al. Circ Arrhythm Electrophysiol, 2016 Jun;9). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	Pathogenic	0.98
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.83	D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.4	H
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.1	D
REVEL	Pathogenic	0.86
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.92
MutPred		0.71		Gain of MoRF binding (P = 0.0026);
MVP		0.99
MPC		1.7
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.70
gMVP		0.99

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: rs730880792; hg19: chr14-23887429; COSMIC: COSV62515838; COSMIC: COSV62515838;